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How Well Does the J&J Vaccine Work Against the Delta Variant?

That’s a question that’s on a lot of people’s minds, because frankly, we have answers that seem to disagree with each other. Let’s have a look:

For one, there’s this letter in the NEJM from researchers at Beth Israel Deaconess hospital and from Janssen (J&J’s pharma branch). That’s a look at immunity in 20 patients who had the single dose (and in a few cases, two doses), versus controls, and it compares serum from these patients against the original strain along with the Alpha, Beta, Gamma, Delta, Epsilon, and Kappa variants, with many of these tested over time to see how the neutralizing antibody levels might have changed over a period of months.

In general, the peak responses were at the Day 71 blood draw, but these had not gone down that much by Day 239 – and still not far off of the values on Day 29, which is good to see, considering that you can already see protection showing up in the clinical trial data even earlier than that. As in other studies with other vaccines, the Beta variant (B.1.351) showed the biggest effects in lower neutralizing antibody titers (most possibility of evading vaccine protection), but that showed an interesting patter. At Day 29, the neutralizing antibody levels were 13 times lower against Beta than they were for the parent strain, but by Day 239, they were only 3-fold lower. This strongly suggests that the antibodies being produced are in fact expanding and evolving in “germinal centers” in the lymph nodes over time (which lead to longer-lived plasma cells in the bone marrow) which is very good to see. That link goes into more details, but basically a good vaccination keeps on going, stimulating your immune system to keep on producing new antibody variants and expanding production of the ones that seem to be doing the best job. We’ve recently had direct evidence that the mRNA vaccines produce long-lived germinal centers, which is excellent news in a landscape that features new variants coming on.

Comparing the variants head-to-head, the single-shot patients at day 239 had a median pseudovirus neutralizing antibody titer of 184 against the parent strain (two-shot patients were at 192). Against Alpha, this titer was median 147, Beta 62 (there’s that threefold drop), Gamma 129, Delta 107, Epsilon 87, and Kappa 171. So as has been said before, while the more infectious delta form is somewhat less neutralized than the original coronavirus is, the spread of the Delta strain (B.1.l617.2) is at least crowding out some variants (like Beta) that are even better at getting past the antibodies. Whether it’s possible to have a more infectious strain that’s as vaccine-antibody-evading as Beta (or worse) is as yet unknown. There might be no amino acid variations possible for the virus to hit on that trick, or it might have done so this morning somewhere. We simply don’t know.

So this work shows that the J&J vaccine still seems to be protective against Delta, albeit at lower levels (but not so low as to break through constantly). We need to contrast those results, though, with this new preprint that came out two days ago from a team at NYU. It’s very similar in its methods: pseudoviruses containing the business end (the Spike protein) of the different coronavirus variants are evaluated versus serum from recovered coronavirus patients as well as vaccinated patients to see what the neutralizing antibody titers are. And this one compares the J&J values to those from people vaccinated with the Moderna and Pfizer/BioNTech mRNA vaccines as well. The actual J&J titer numbers I’m about to show should not be directly compared with the ones just mentioned above, but the trends can be.

I’ve assembled the NYU data into one table below. The convalescent numbers are the mean values from 8 different patients, the Pfizer/BioNTech ones are a mean of 9 patients, the Moderna ones are a mean of 8 patients, and the J&J ones are a mean of 10 patients. The standard deviations on these numbers are fairly large, since different patients responded differently. But even this sort of spread is definitely not large enough to wipe out the larger differences that we’re seeing between vaccines (and versus convalescent patients who went through the immunity process the all-natural way). The convalescent data were collected somewhat earlier than the vaccine sera, as you’ll note, and we saw from that NEJM paper that the J&J antibody titers (in their samples, anyway) peaked at their Day 71 sample. So it’s possible that the convalescent data might look a bit better at a later time point, but they’re surely still not going to hit the levels seen in the mRNA-vaccinated patients.

But these numbers do not make the J&J antibody levels look good at all. They’re worse than convalescent patients, and as mentioned, these samples were presumably collected around the peak of the J&J levels if we can draw that conclusion from the earlier NEJM paper. I am sure that the appearance of this preprint is causing consternation at J&J, and I look forward to any statements that they might make on it. So far, their comment seems to be that these new numbers “do not speak to the full nature of immune protection“. That same New York Times article linked also quotes an author of the NEJM paper (from Beth Israel Deaconess) saying that he doesn’t feel that the numbers really look that different, but I can’t really see that. He also notes that the new preprint does not touch on T-cell numbers (the NEJM work showed what appear to be durable CD8+ cell numbers). That’s a fair point, and T-cell data always lag antibody data because the numbers are so much harder to obtain (which means that we have only a fuzzy idea of the importance of T-cells as a part of the total immune response to the coronavirus, although they must surely be important.

But even taking all this into account, these NYU numbers, if they are indeed what they seem, would indicate that the single-dose J&J vaccination might well have a greater chance of losing efficacy against variant strains. The huge majority of people being hospitalized with Delta infections here in the US are not vaccinated at all, as we’ve all been hearing, and that just makes you want to beat your head against the wall in general, because we are, horribly, well stocked with vaccine doses that are going unused while the people who are passing them up are getting sick. But we also should be collecting data on the far smaller cohort who have shown serious disease after having been vaccinated, and see if there’s a trend for single-shot J&J patients to stand out in that group.

I would certainly think that these data are being collected – if they’re not, we have still more problems – and I hope that we can get a read on this. It’s the actual patient numbers that are the most important here, and that’s what we’re currently lacking. . .

109 comments on “How Well Does the J&J Vaccine Work Against the Delta Variant?”

  1. NumCracker says:

    Hi Derek,

    could you please provide us with comparative data also including the AZ vaccine? Guess its efficacy loss would be even worse than J&J compared to Beta, but not to Delta VOCs.


    1. AVS-600 says:

      I could be mistaken, but I think both studies were run at hospitals in the US, where AZ as-of-yet lacks an EUA. So that data probably just doesn’t exist.

      1. Siddharth Dasgupta says:

        Just saw this paper in NEJM
        From Conclusions:
        Only modest differences in vaccine effectiveness were noted with the delta variant as compared with the alpha variant after the receipt of two vaccine doses. Absolute differences in vaccine effectiveness were more marked after the receipt of the first dose. This finding would support efforts to maximize vaccine uptake with two doses among vulnerable populations. (Funded by Public Health England.)

        They investigated BNT162b2 and ChAdOx1 nCoV-19.

        1. Nate says:

          Using a logistical regression in that study is laughable. The tests they offer are full of assumptions. Reading the methods reveals nothing close to dichotomy.
          How about they incorporate the CD8, th responses in symptomatic vs. asymptomatic and delta vs. beta vs. alpha (this is all documented)
          Furthermore this seems like confirmation bias to me. It is the same thing that was pulled during p3. The studies were not blind…
          Several things…People who get vaccinated are also far more likely to socially distance and wear a mask and not be a total reckless ass hat. Antivaxxers are, you guessed it, ass hats; and my guess is in the UK (I haven’t been recently due to the pandemic) the antivaxxers are like trump supporters on steroids.
          I’m not saying they’re wrong, but the methods are flawed and to make a claim like 93.7% effective against the delta variant for PFE when it’s plain as day what’s going on in Israel is absurd in my opinion.

          1. David says:

            I would agree with your assumption that people who get vaccinated are also more likely to listen to medical advice etc.
            Can you do a controlled trial only among people who don’t believe in the existence of COV-SARS-2 or vaccinations?

    2. John Beaumont says:

      The data from the UK would suggest there is only a slight difference between mRNA and AZ for symptomatic infection.

      – Pfizer 85-95
      -AZ 75-85

      And for severe disease efficacy is in the 90s.

      Table 1, page 6 here

      Public Health England has a range of similar reports – some that are more comprehensive and seem to show same thing: AZ marginally less effective at symptomatic, same as severe.

      1. Not-an-epidemiologist says:

        That’s not the case at all: against Delta, effectiveness against symptomatic disease for Pfizer was 87.9% (95%CI: 78.2 to 93.2), whereas AZ was 59.8% (95%CI: 28.9 to 77.3) (see

        AZ still protects well against serious illness, but for countries like the UK those numbers pretty much put an end to any hopes of herd immunity (not that Delta gives you much hope on that regardless, unless you’re in Iceland or Canada).

        1. John Beaumont says:

          That PHE study you refer to was several months ago when few AZ vaccinated folks had a second dose. The AZ vaccine seems to take longer to build immunity. If you read the link it states this (as a possibly hypothesis, not a fact).

          The table I referred to is updated every week by PHE its vaccine effectiveness report so I think is more current.

          It is interesting that the recent Israeli work suggests Pfizer efficacy against symptomatic disease for Delta is in the 60s …

          Now obviously in real world you are not running a proper trial so you need to take that into account when interpreting data. What does seem to be true is that severe disease is a lot less in any of the vaccines, which is the most important thing.

          Personally I am intrigued to understand the efficacy benefits of a mix vaccine strategy.

          1. Maringer says:

            Unfortunately, John, I think you’ve misread that table. The heading reads:

            “Table 1. Summary of evidence on vaccine effectiveness against different
            outcomes (data relate to period when the Alpha variant dominated)”

            The 75% – 85% number relates to the period before Delta was a factor. The only evidence for AZ efficacy for symptomatic disease against Delta I’ve seen is the 60% figure quoted by PHE.

            As a recipient of the AZ vaccine in an area where Delta is running rife at present, I wish the efficacy was higher!

          2. Not-an-epidemiologist says:

            Yes, it was made out of date just as I was writing that comment, and my apologies — the final version was published in NEJM yesterday, and the figures have been updated with tighter CIs. Against Delta, the results were:

            Pfizer: 88.0% (95% CI, 85.3 to 90.1)
            AZ: 67.0% (95% CI, 61.3 to 71.8)

            This is a bit of a welcome improvement for AZ, but there’s no doubt that it’s the weaker vaccine of the two (although of course still much, much better than no vaccine!) The “takes longer to build immunity” throw-away line is worth the evidence it’s based on, IMO — I saw it more as an attempt to try to save ChAdOx’s blushes by PHE (similar to the way that these data always get combined into one set of figures in the PHE reports, a bit embarrassingly). Anyway, that part of the discussion has been moved to supplementary material in the published paper, which probably says a lot about how credible even the authors thought it. But, you know, it’s … possible.

            Heterologous vaccination (AZ / Pfizer) looks great, btw. Canada’s been doing this for months, there’s substantial data supporting the idea that you get a very strong immune response, and I don’t get why the UK isn’t doing this already. But the UK has been very reluctant to see the defects in their home-grown vaccine all along.

            I don’t think anyone’s seen the Israel data that claimed an efficacy reduction for those immunized six months ago? (And there were some rather transparently pecuniary motivations for Pfizer pushing these data so hard, which I think has left a sour taste in most people’s mouths.) It’s impossible to say anything more without seeing the figures, but a couple of clear issues would be that any study must be based off extremely low numbers (there just aren’t that many people who’ve been infected with Delta in Israel in total, and many of the infections have been in younger age groups who weren’t vaccinated six months ago).

          3. Tony M says:

            John worth summarising:

            Estimate vaccine effectiveness against symptomatic disease:


            BNT162b2 vaccine…………………………………93.7% ……………………88.0%

            ChAdOx1 nCoV-19 vaccine…..,,…………………74.5%,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,67.0%


          4. Mariner says:

            As a recipient, I’ll not complain about an improvement in protection indicated by this new data!

          5. John Beaumont says:

            Yup. That is my understanding. And that is against symptomatic disease. Against severe / death I think

            – Pfizer is the 96% range
            – AZ in 92% range …

            Sounds similar but when you do the maths AZ death rate is double Pfizer, but still v. v. v. low compared to no vaccine.

            The one bit of data that needs more triangulation is the Israeli data on Pfizer suggestion mid 60s efficacy. I can’t find a pre-print with the data in …

  2. Andy says:

    Hey Derek,

    Just want to thank you for your always-informative posts. You’ve consistently been a level-headed, thoughtful bridge between the research world and the interested layperson throughout this pandemic (and before, I’m sure, though this is how I found your blog). Always excited to read a new entry from you for great context and perspective. Keep doing what you do, please. That’s all!

  3. Adrian says:

    Protection against Delta plus seems to be better than protection against Delta. Not statistically significant, but at least in this limited data Delta plus does not appear to be worse.

    1. Charles H says:

      With sample counts below 10, I don’t think that ANY of the results are statistically significant. There’s too much variability within humans. But it’s a significant indication. And makes me glad my vaccination wasn’t J&J.

      In this kind of environment you can’t expect to get the data you want, so you’ve got to place your bets based on the data that you’ve got.

  4. Adrian says:

    “Whether it’s possible to have a more infectious strain that’s as vaccine-antibody-evading as Beta (or worse) is as yet unknown.”

    Based on this (very limited) data, only for the mRNA vaccines Beta is actually worse than Delta.
    The convalescent and J&J data indicates that Delta might be as antibody-evading as Beta in these groups.

    1. Adrian says:

      Any such observations might turn out to no longer be true in statistically significant results, but it might turn out that some variants might evade protection from some vaccines but not from others.

    2. Roland says:

      Presumably Convalescent bloods were from D614G & Alpha infections (the responses to each suggest a mix). So Beta & Delta are evading those, but whether Delta infection (also vaccine + Delta infection) gives good protection against Beta is unknown and could become important.

      If it’s good enough Beta could die out as Delta achieves world domination. If it’s the same or worse as the D614G & Alpha infections then Beta will probably rumble on long after Delta has washed through and strike vaccinated or pre-infected individuals every time their immune system has a bad day.

      More generally I don’t yet think it’s inevitable we’ll live with this forever. Delta is so damn infectious it could burn itself out globally within a year or two. The immunity pattern it leaves will be crucial. The fact infected children are less contagious is an important detail too, because those will be the never-ending supply of naive hosts the virus may need to sustain itself in. If it does all go away it’ll be *because* our modern world is so connected there are no pockets to hide in, which I think would be a very pleasing twist on the whole modern pandemic problem.

      Or maybe I’m being optimistic and there’ll be enough forever-infected individuals to reignite Covid every few winters.. Is anyone taking bets yet?

  5. luysii says:

    The following real world data is worth considering. Source:

    4,360,000 vaccinated in Massachusetts

    4,450 breakthrough cases — so the vaccines are incredibly effective with an efficacy rate of 99.9%.

    No drug is perfect. Don’t forget that there are many immunosuppressed people (cancer, transplants) living in Massachusetts who don’t respond to vaccines as well. This efficacy rate is vaccine efficacy as it is defined. For the efficacy that people actually care about see below.

    92% weren’t sick enough to be in the hospital — which is why the use of ‘case’ for these people is sooo misleading

    There were 79 deaths (but not all in the hospital — some probably were in nursing homes)

    So the real efficacy which docs and patients care about (e.g. not getting sick enough to be hospitalized ) is 10 times higher than 99.9% at 99.99%

    The risk of death from COVID-19 after vaccination is 1/100,000

    I suppose that, as Delta hangs around in the community, the vaccinated will be re-exposed, so there might be more breakthrough cases in the future.

    1. Adrian says:

      Sorry to say, but your math is rubbish.

      There were 12,423 deaths from COVID-19 in Massachusetts in 2020, which (according to your math) shows that not being vaccinated has an efficacy of 99.8% against death from COVID-19.
      This 99.8% is as wrong as your numbers.

      Fake news like your “vaccines are incredibly effective with an efficacy rate of 99.9%” only make it harder to have a proper discussion on the real benefits and limitations of vaccine protection.

    2. Bill says:

      The number of people vaccinated is a matter of record.

      The number of breakthrough cases is only a tally of positive test results. Typically only patients with symptoms would seek out testing leaving the asymptomatic cases not counted. Breakthrough infections are said to typically produce few to no symptoms.

      And Our World in Data shows that the testing rate in the US has sunk to lower than 3rd world numbers.

      IE, we have no idea of how many breakthrough cases are accumulating. So calculations based on them are worthless.

      1. luysii says:


        “Typically only patients with symptoms would seek out testing “. Not so. Pretty much anyone having a hospital procedure for anything must be tested a day or so before proceeding. Soon, going to Canada will require it.

        If most breakthrough ‘cases’ are asymptomatic as you note, why should you care about them at all? The use of the term ‘case’ for an asymptomatic infection is semantically dishonest and misleading. We have more microorganisms on and in our bodies than cells. Are we all cases?

        Then there are the statements of the Surgeon General and the CDC to consider

        “There’s a common theme among those behind the worsening COVID-19 numbers, said Dr. Rochelle Walensky, director of the US Centers for Disease Control and Prevention:

        “This is becoming a pandemic of the unvaccinated,” Walensky said at a COVID-19 briefing Friday.”

        More than 97% of people getting hospitalized with COVID-19 now are unvaccinated, Walensky said. And 99.5% of deaths are among the unvaccinated, US Surgeon General Dr. Vivek Murthy said Sunday.”


        1. Bill says:

          “If most breakthrough ‘cases’ are asymptomatic as you note, why should you care about them at all?”

          The reason you care is anyone who is infected has the potential to infect others…including people still at risk. We can argue how probable spread is, case by case basis. But I doubt anyone really knows for sure yet.

          1. Philip says:

            Bill, we have an idea. “Overall, the likelihood of household transmission was approximately 40 to 50% lower in households of index patients who had been vaccinated 21 days or more before testing positive than in households of unvaccinated index patients; the findings were similar for the two vaccines (ChAdOx1 nCoV-19 and BNT162b2 vaccines).”

            Link to the paper:

          2. Chris Phoenix says:

            Children have a significant chance of long covid (3 to 10+ % based on age, from the England study I read). Long covid includes an 80% chance of lack of smell, which sounds to me like brain damage.

            Cutting household transmission rates by 50% is _not enough_ to make this vaccinated parent comfortable with going out and exposing myself to Delta.

          3. Mariner says:

            As a follow up to Phillip’s comment, I should point out that the NEJM study he linked relates to the infections during the period before Delta was a factor. Delta is much, much more transmissible even than Alpha. I remember reading a report somewhere that attack rate within a household has been pretty much 100% in the outbreaks in Australia. They’ve obviously had a lot fewer infections than most developed countries and have been able to track most of the spread so are more likely to have accurate information in this regard than elsewhere.

            Here in the UK, it seems to me that a lot of decisions are being made (you would assume knowingly) with reference to the studies that show, “Children don’t spread the virus” and “Children aren’t badly affected”, all of which information were in the pre-Delta times. Heck, some of the studies quoted were before Alpha emerged.

            I don’t imagine that the medical professionals quoting these studies are dim enough to miss the fact that they are hopelessly out of date given the rapid evolution which has led to the newer variants, which makes me believe some gaslighting is going on to justify the decision to let infections rip through the unvaccinated, mostly children and young adults.

        2. theasdgamer says:

          Here’s another data point.

          The hospital where my wife works sent out an email that the majority of hospitalized covid cases are vaccinated, despite the county only having about a 50% vaccination rate. And the age varies a lot between middle aged and under 70 elderly.

          1. Albert says:

            This is a pandemic of the unvaccinated! What a hoot.

          2. David says:

            I wonder, just as a data point, are the vaccinated older than the unvaccinated? Could that have anything to do with it?

          3. Ravenous Bugblatter says:

            How astonishing, it’s almost as if those people thought to be vulnerable to hospitalisation for one reason or another had been selected to get vaccinated first.

          4. David says:

            Here is a nice explanation, for those who don’t understand why vaccinations has not solved the pandemic, but still work and are the most important tool we have to get back to ‘normal’ (
            The vaccines lower transmission, infection, severity, hospitalizations and death, bot don’t eliminate it.

          5. achemist says:

            By itself thats not surprising.

            The first part of the population that was vaccinated were the people with risk factors (and afaik they had good vaccination rates as well).
            If 99% of a population is vaccinated with a vaccine 99% effective against hospitalisation there will be 50% vaccinated people in hospitals.

          6. NewsView says:

            Earlier this year a UK “Roadmap to Recovery” document predicted, without accounting for variants, that by Fall 60-70% of hospitalizations will be among the vaccinated. The attribute this to the fact that the vaccinated make up a higher share as compared to the unvaccinated. However, already in portions of California high-vaccinated counties (Bay area, Los Angeles) are seeing high rates of cases/hospitalization whereas low-vaccination counties, relatively low case rates. This may be out of date but a week ago I visited a website where Delta cases were mapped and it showed that Florida and California were both both high-Delta transmission states. However what was unexpected was that two of the leading states for vaccination — Rhode Island and Maine, where vaccine rates are about 10% higher than anywhere else except for Connecticut and Hawaii — also led the list. This doesn’t fit the narrative that Delta is a “pandemic of the unvaccinated”.

            Does the UK’s explanation for more hospitalizations among the vaccinated this Fall/Winter add up? (I suppose one possibility is vaccine rates were highest among older at-risk populations who, according to data out of Israel and a recent CDC admission, apparently remain vulnerable vaccinated or not.) At any rate, if UK’s explanation is that one would expect more hospitalizations to be among the vaccinated simply by virtue of the fact that more people are vaccinated than not, how would one know whether ADE has entered the picture?

          7. Derek Lowe says:

            Please look more carefully into the data before you post: Maine and RI are nowhere near the top of any coronavirus lists at present:


    3. David says:

      The efficacy of the vaccine at preventing death cannot be computed only from data on deaths in vaccinated people. You also need the corresponding data in unvaccinated people, and then you can compute relative risk.

      From the linked article, and also from the article it in turn links to (rounded):
      Vaccinated, dead: 71. Vaccinated, not dead: 4.195M
      Not vaxxed, dead: 4,986 Not vaxxed, not dead: 634k
      (lower right N computed by subtracting 4.195M from adult population of MA, from google)

      A relative risk calculation shows that unvaccinated people are 460x more likely to die. 99.8% efficacy.

      However, this is a bit biased, since the people at highest risk of death (elderly, ill) are more likely to be vaccinated, so the vaccine is even more effective than that.

  6. Adrian says:

    “would indicate that the single-dose J&J vaccination might well have a greater chance of losing efficacy against variant strains.”

    Here in Europe in many countries people who got the AZ vaccine as first dose later got Pfizer as second dose (when the safety issues of the AZ vaccine in younger people became known between their doses).

    This data would suggest that people who got the J&J vaccine might later be offered one dose of the Pfizer vaccine as booster.

  7. Anon says:

    A side note, but isn’t this data unfair to the convalescent group, as their blood draws were likely short of the peak immune response date?

    1. Charles H says:

      Yes, and that was indicate, though not emphasized, in the text. But the question being addressed was how does the J&J vaccine stack up, so that was appropriate.

  8. Big Fool says:

    This is not an exact comparison, but they found that 94% of breakthrough infections amongst healthcare workers in South Africa who had been vaccinated with the J&J vaccine were mild.

    “Consistently we are finding that 94% of breakthrough infections are mild, 4% are moderate and only 2% severe.”

    B1.351 is much better at piercing the immune response than any other widespread variant – in this in vitro study, the titers were half of the level of those developed against Delta:

    Now it could be that the healthcare workers were taking enough precautions that they would be far more likely to have milder infections, but 94% mild breakthroughs is very good.

    I think we’ll see the J&J vaccine have an efficacy against symptomatic Covid in the 60% to 65% range, as it had against P.1 and 1.351, at least for now, and those who do get it will likely have a mild case. Whether that will hold up for 12 months or more, we’ll have to wait and see.

    I think that it’s far more important to get the unvaccinated to become vaccinated with the J&J, AZ or mRNA vaccines than it is to worry about J&J efficacy, especially in the United States, where far, far too many are playing the game of, “My immune system will keep me safe from this imaginary disease, so I don’t need these vaccines, which are a plot to poison us by the Deep State and Big Pharma.”

    Anyone who can poke holes in my deductions based on Derek’s write up and these study results, feel free.

    1. K.S. Miro says:

      Is this a fear that testing J&J recipients, or the immunocompromized (J&J or mRNA recipients), will harm efforts to vaccinate others?

      That’s a risk-benefit calculation that needs to be made openly. If the risks of testing and a boost to J&J or IC recipients outweighs the benefits specifically to these recipients, that’s one type of decision. If instead you’re arguing that the benefits exist to them, but the hypothetical risks to other people outweigh these benefits, that’s not the same.

      Asking the IC or J&J recipients to continue living with a risk that could be mitigated with testing and a booster, a risk mRNA recipients don’t have to face, just to protect marketing and messaging? That’s not a decision that should be made behind closed doors.

  9. Adrian says:

    I hope this paper get a peer review from a mathematician.

    Comparing J&J Beta:Delta numbers is 33:30 in the data you copied into your table, but based on the data in the study J&J donor 8 (7 for Delta, ND for Beta) is counted for Delta (reducing the average) but ignored for Beta (where the result was even worse).

    I wonder if ND should be interpreted as 0, which would give 26:27 instead.

  10. Mark says:

    Thank you Derek for writing in terms that a layman can grasp. The obvious question that comes to mind for those that received the single shot J&J vaccine, should they get a second shot and if so, of the same vaccine or one using mRNA? The latter seems to be better based on mixed shot studies against the similar AZ vaccine. If that’s the case would waiting for the updated version of the Pfizer-BioNTech vaccine that targets the full spike protein of the Delta variant be preferable? I suppose these are rhetorical questions until more research is made available (particularly related to your final paragraph).

  11. Dian says:

    In both studies the N for the groups is small. The data from NYU compares all three vaccines head to head in the same assays which is important if you want to compare them. Clearly the response is lower from the JNJ vaccine in that study. The BI study only looks at those who got the JNJ vaccine. The important question is do they all protect against severe COVID–19 hospitalization and death. Real world data will answer this but that will be lagging.

    1. 이웅견 says:

      heh, yes, xkcd is often really brilliant:)
      permalink is

  12. TallDave says:

    wow those J&J numbers… do they translate to mortality? (probably, but proof is nice to have, as we’ve learned)

    Moderna seems to have picked the right proteins to program our cells to spew around our bodies… somewhat ironic that the first vaccine is also still the best vaccine, but even as a longtime MRNA cheerleader don’t think it will be true indefinitely

    high hopes for UB-612, they should hurry this up — the multi-epitope approach may yield even higher effectiveness against the variances of the various variants

    and given the cost/distribution advantages, if this platform is viable we might just stamp this thing out in humans (while mRNA vaccines crush malaria, we can hope)

    people not vaccinating is exasperating, but at least US excess deaths are back to near normal, hopefully that lasts through winter

  13. Julie says:

    So if you had COVID (thus antibodies) and got the J&J shot, was that vaccine the booster that may be needed? Would it be a detriment to simply go get a single Pfizer shot now to head off lines later?

  14. remember W French A says:

    Remember this hydroxy charlatan, Doctor Vinnie Boombatz Didier:

  15. Barry says:

    People will continue to treat IgG titers as if they were the whole immune response because IgG is easy to measure. Unfortunately, we’ve known for a year now that it’s a weak surrogate. Cases are documented of full recovery from Covid w/o mounting any IgG response (presumably innate response sufficed?) and many cases are known where whopping IgG response was just part of the immune over-response that eventually proved lethal.

  16. Albert says:

    We are seeing analysis of current figures out of Israel suggestive of complete failure for mRNA vaccines vs. Delta take a look, analysis here is based on official data.

    1. David says:

      I stopped listening to the ‘great’ Prof. Levitt when he wrote (on July 25, 2020) that the pandemic would be over by August, with <200,000 deaths in the US.
      Such an accurate prediction

      1. TallDave says:

        yep if we’ve learned anything it’s that no one should make those predictions, way too contingent

        heck had H2H trasnmission been acknowledged from the beginning of the initial outbreak in Wuhan and appropriate measures taken, the virus might well have been contained locally and most of the world might never have even heard of it

        hopefully we are in fact learning, harboring serious doubts

  17. James Donovan says:

    Thank you for this incredibly informative article.
    Sorry for the layman’s questions, but why can we not directly compare the numbers shown in your table between vaccines? Doesn’t this show that even on the alpha strain the J&J is raising 3x or more fewer antibodies than the mRNA vaccines? Why would this not be reflected in efficacy against the wild type strain?

  18. Albert says:

    Weird scenes inside the gold mine regarding PfizerBNT and Gamma failure

  19. duane schulthess says:

    The overall case fatality rate for Delta in the latest Public Health England report is .02%, compared to Alpha’s which is 1.9%, or put another way, 9500% higher…

    Delta, with an R of 6, appears to already be declining rapidly in rate of transmission in the UK since first increasing the case numbers on or around May 1st.

    May 1st – May 31st, 1907 to 3111 cases; Increase of 163%, daily avg delta, 5.26%
    June 1st – June 30th, 3099 to 25606 cases; Increase 826.3%, daily avg delta, 26.65%
    July 1st – July 15th, 27556 to 47891 cases; Increase 173.8%, daily avg delta, 5.61%
    July 16 – July 21st, 51273 to 43404 cases; decrease -15.3%, daily avg delta -.5%

    Let’s just say I’m not cancelling my vacation…

    1. Albert says:

      For sure Delta is less deadly India with no vaccines maintained low deaths / million population all through their delta wave. UK cases +37% WOW and deaths +60%, infections in vaccinated cases are the difference, what mutations may emerge from the UK, European or US delta wave is anybody’s guess. Could be pretty bad, from experience the wave will be pretty rapid to pass over, hopefully no escape variants are washed up on shore. Many predict this

      1. 이웅견 says:

        Well, I for one am not so sure about numbers from India, the government there doesn’t seem to suffer too badly from excess morality.

        1. Oudeis says:

          Ha. I read that as “excess mortality” three times before I realized what you were actually saying.

      2. David says:

        Many predicted what, exactly? That the virus will mutate? That a vaccine would be less effective vs. another variant? I think that everyone expected that

        If most (older) people are vaccinated (and the disease is more infectious to older people), then it wouldn’t be surprising that most cases are in vaccinated people. If most people at risk are vaccinated and the vaccine lowered the risk for severe infections, then it wouldn’t be surprising that hospitalizations/mortality is down (such as in Israel).
        Does this mean that Delta is less fatal or that Delta is about the same and the vaccine lowers fatality? I don’t know – Do you?

        1. Albert says:

          Predicted exactly the course that virus will take (to full escape mutations) in the presence of antibodies elicited by the vaccination campaign. This will happen much quicker with leaky vaccines (as it’s clear that we have). See here for details and large body of evidence supporting this hypothesis.

          1. David says:

            This seems to be an interesting theory. And I agree with the authors and their call for better handling of the spread – we need more vaccines and more vaccinations. What options do we have? What do you think we should do?

            The paper doesn’t deal with cases of vaccination+(milder)infection (or the other way around). I wonder what kind of immunity that would generate.

            Just remember, none of the current VOC needed mass vaccinations to mutate and become the dominant variants.

          2. Tony M says:

            Albert, using data from the English PHS VOC Briefing 18 and using England vaccination population statics as at 30 June on the Delta Variant:

            I get than comparing a fully vaccinated person to an unvaccinated person:

            Over 50s:
            An unvaccinated person was: –
            – 4.9 times more likely to get infected;
            – 11.9 times more likely to require overnight hospitalisation;
            – 12.4 times more likely to died;

            Under 50s:
            An unvaccinated person was: –
            – 4.6 times more likely to get infected;
            – 7.2 times more likely to require overnight hospitalisation;
            – 3.8 times more likely to died;

            This does appear to be direct contrast to the Israel data.

            Perhaps someone from England can ask their member of parliament to request data split down more detailed on the different vaccines and have the age groups more detailed (as opposed to just Under/Over 50s)?

        2. Duane Schulthess says:

          The previous public health England report (June 26) broke out the unvaccinated CFR data for all over 50 years of age for Delta, which was roughly 4%. Vaccinated CFR was roughly 1.4%. However, 98% of current unvaccinated infections are in the under 50 population, and that is what drives the combined CFR down to .02% for the entire Delta cohort, which is extremely low of course.

          Pre-Delta and vaccines, crude CFR for 60+ was roughly 1.5%, 70+ was 6%, 80+ was 20%. So, no matter how you slice it, vaccines radically lower risk, and Delta seems far less virulent than Alpha.

      3. Tony M says:

        “For sure Delta is less deadly” I wouldn’t necessarily conclude that:

        Based on World Meter, the UK has a mortality rate to date (pre and post vaccination) of 2.3% (=128,980/ 5,602,321)

        Using data from England PHS :

        I get the mortality rates for Unvaccinated from the Delta Variant:
        Under 50s………….0.0297% (= 21 / 70,664 )
        Over 50s……………5.604% ( = 71 / 1,267 )

        With England having a population of 39.1M under 50 and 21.3M over 50, the delta could be expected to have a mortality rate of 1.99% if all the population was unvaccinated and those percentages prevailed.

        1. David says:

          Here is some data from Israel, showing the difference in severity (hospitalization), between vaccinated and not vaccinated populations (

  20. Oudeis says:

    So, something I’ve been wondering about (and my apologies if earlier comments covered it): why do the more transmissible variants crowd out the less transmissible ones?

    This non-epidemiologist would have imagined that they’d all continue in circulation; you’d just see a lot more people with the more transmissible variants. But the esteemed blogger here (no sarcasm intended) suggests there are actually fewer cases of Beta in the world because the more transmissible Delta variant evolved, and the graphs I’ve seen showing distribution of variants over time would seem to back him up. Does anyone know why that should be the case?

    I guess maybe Delta, spreading faster, is inoculating people against Beta and making it harder for Beta to spread? But surely there are still plenty of people for Beta to infect–the number of people catching Delta (in the U.S. at least) is still a lot lower than the number of people being vaccinated. It doesn’t seem like that rate of Delta inoculation should make that big a difference to Beta’s spread.

    1. TWiV fan says:

      Vincent Racaniello and the TWiV team are very keen on correcting the language here. Check out Ep #777. You will hear that there is no evidence for increased transmissibility (there can’t be, because that sort of experiment is unethical). Delta has better fitness, which is a product of multiple factors, probably most notably immune evasion. It faces a larger susceptible population, thus it spreads while other variants are snuffed out.

      As for his thoughts on the lab escape hypothesis and gain of function, I’m not so sure. But I appreciate his crusade to bring awareness to the fitness vs. transmissibility nuance.

      1. Philip says:

        Beware the English language. Some words have very precise meanings in some professions, but different meanings to other professionals and even different meanings to lay people like me.

        To me any virus that infects more people is more transmissible. For a viroglisist more transmissible seems to mean a lower infectious dose or possibly staying infectious longer in the environment. Fitness on the other hand could be the ability to reproduce more quickly in an individual. I hope I got that correct.

    2. Ted says:

      It’s easiest to just think of it as a competition for the remaining available hosts. Every time a variant finds a new host (I like the image of the Godzilla car from Death Race 2000, but I’m a bit damaged in some regards…), it spreads out from that base, while simultaneously preventing the other variants from doing the same. As for the host, it becomes resistant for a time (permanent in the case of death) to most variants, with some wiggle-room there for low level reinfections. Variants like the beta form will eventually be boxed in by resistant patients (i.e. not Alabama, Arkansas, etc…) with no new hosts within range.

      Given the recently reported data on 2 – 3 order of magnitude increased viral loads for patients infected with delta variants, fitness vs. transmissibility seems like a pretty minor quibble. This is a pretty dramatic shift, and points to a fraught future. India may finally be approaching herd immunity (the hardest possible way), but most of Africa has a long way to go.


    3. Calvin says:

      This is an acute viral infection so there is no circulating virus that hangs around in a person for more than a few weeks. Once it’s gone, it’s gone. So the circulation is from one person to another. Since Delta is so much more infectious, it will out compete the other variants because it can infect more people in a given amount of time. That time component is what drives things because infection has it’s own time course which is short.

  21. Anon says:

    Imagine publishing an article with an N=10. I am not saying the results are rubbish but you wouldn’t even present this to your colleagues in normal times…

  22. Ted says:

    All the more reason to be excited that this trial is being run:

    I don’t believe the Janssen vaccine was included in any of the UK mix-and-match studies, correct?

    Hopefully they’ll focus the results on the neutralizing antibody counts vs. the currently known variant strains.

    I wonder if the variant strain nomenclature won’t invert hurricane protocols, and jump from (greek) alphabet into names: chi variant, psi variant, omega variant, Alex variant, Ben variant, Chad variant, Don….


  23. john says:

    “Against Alpha, this titer was median 147, Beta 62 (there’s that threefold drop)….”

    That is IMPOSSIBLE as in the real world Beta never competes against the other varieties. They all go their independent ways and all flourish.

    1. John says:

      My bad. I saw the “here’s that threefold drop” and thought this was related to the belief that “Beta is disappearing from the world thanks to Delta being much more transmissible”. It is this that is IMPOSSIBLE, because the Beta and Delta never compete. They would both go their independent ways and both flourish.

  24. Michael says:

    What I find suspicious about the second set of results is that they don’t match the pattern seen in the phase 1&2 antibody measurements. As I recall, Moderna (and Oxford) produced a level comparable with the benchmark seen in mild/moderate disease convalescents, whereas Pfizer (and Novavax) stimulated antibody production 8 to 10 times higher. (Jansen’s results were the worst of all, lower than in convalescents). Here, Moderna’s results are the highest, despite their having previously reported a proportionally similar reduction in antibody response to variants as Pfizer. Something isn’t right.

  25. Ryan says:

    Something that bothers me (quite a lot) is that I have seen very little public news regarding understanding of the disease’s etiology. Early on I remember a lot of fuss about abnormal hemoglobin / heme / iron binding leading to hypoxemia etc. It wasn’t just straightforward ARDS. All of the recent news has been about vaccines and nothing else.
    As we know that the vaccines don’t have 100% efficacy, especially given variants, it would seem valuable to have a handle on the etiology to expand treatment options. I’m presuming that research has been conducted and it just hasn’t been publicized much, for whatever reasons. Maybe nothing interesting has been discovered?

  26. Nigel says:

    This is very off topic , but a genuine question . This document
    has become very popular with the anti pcr people . I came across it on Dr Campbell’s YouTube channel. Unfortunately it and the links are rather too technical for me . I would much appreciate some help answering these people.
    All the best.

  27. Nigel says:

    Here’s an example of what people are saying.
    39 minutes ago (edited)
    Thoughts about the FDA removing emergency use for the PCR tests…they’ve all been recalled ..
    …( and not just any recall …a class 1 recall )
    Plus the Covid / flu aspect.

    1. theasdgamer says:

      Maybe the PCR test will be approved, so no need to keep it under EUA any more? Make room for new tests that perhaps will be able to distinguish between flu and covid for clinical use?

      There can be many reasons for withdrawing the PCR EUA. It’s strange that the CDC doesn’t explain further.

      1. David says:

        I would think that this line ‘CDC is providing this advance notice for clinical laboratories to have adequate time to select and implement one of the many FDA-authorized alternatives.’ would be enough for everyone to understand.
        Labs can’t just switch one diagnostic device (and method) for another at the drop of a hat. There are numerous protocols for method development, validation and approval that take lots of time.

        1. David says:

          And this notification gives >5 months to prepare

    2. Robin says:

      Hi Nigel,

      All this is saying is that the current tests are positive for covid-19 and negative for all else. You could have a subsequent flu test (if negative for covid). So it is false that the current test gets positive for flu too.

      In the new tests, they want the test to say whether someone has covid-19, flu or neither. This saves time and money. By forcing all labs to do this, CDC can keep accurate track of flu too.

      1. Robin says:

        Ah, they are not forcing, but encouraging.

      2. Nigel says:

        Many thanks for the replies .

        1. David says:

          You can find a more detailed explanation here ( and a list of >250 approved tests/kits here (
          This is more of a procedural thing (Anyone who has worked with the FDA knows that they love procedure to a fault).

  28. JasonP says:

    Am I looking at the numbers correctly?

    35 M cases of Covid-19 in the USA
    188 M Fully or partially vaccinated
    223 M – total

    223/330 (total Population) = 67.6 %

    So aren’t we close to ‘herd immunity?” 2.4% ?

    Why aren’t the cases of COVID-19 counted toward herd immunity figure?

    1. The Moar You Know says:

      Herd immunity figure, thanks to Delta’s increased R number, is now no longer 70%. It’s 90%.

      COVID recovered should not count IMO because of the rather large percentage of them that get reinfected. Natural immunity is just not terribly effective against this virus. I hope someone is looking at why that might be.

    1. ToI says:

      “But as the numbers ignite concern among Israelis, even the government’s top expert adviser on coronavirus questioned their integrity. The approach taken could result in a “horribly skewed” outcome, argued Prof. Ran Balicer, chairman of Israel’s national expert panel on COVID-19.

      “Any attempt to deduce severe illness vaccine effectiveness from semi-crude illness rates among the yes or no vaccinated is very, very risky,” he maintained.”
      “A technician collects a swab sample for COVID-19, at a testing center in Tel Aviv (Miriam Alster/Flash90)

      Vaccine effectiveness in preventing serious COVID-19 infection among the elderly has fallen to 50 percent, according to new Israeli figures, but some prominent experts are saying the data shouldn’t be taken seriously.

      The Pfizer-BioNTech coronavirus vaccines were wowing Israelis with sky-high effectiveness rates until the rise of the Delta variant. But according to data recently raised at a top-level Health Ministry meeting, the immunization’s effectiveness in preventing serious illness is now at 80% for the general population and 50% for the elderly.

      Israel’s national research body for epidemiology, the Gertner Institute, conducted the research, and Dr. Amit Huppert from its bio-statistical unit told The Times of Israel that policymakers should pay attention.

      The government “should not be panicked but should take the data seriously, as it’s a warning that should not be ignored,” he said. “Most of us did not believe a month ago we could be in this situation.”

      He added that policymakers didn’t pay enough attention to data on the Alpha variant which arose in Britain and spread quickly in Israel in early 2021.
      Get The Times of Israel’s Daily Edition by email and never miss our top stories
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      But as the numbers ignite concern among Israelis, even the government’s top expert adviser on coronavirus questioned their integrity. The approach taken could result in a “horribly skewed” outcome, argued Prof. Ran Balicer, chairman of Israel’s national expert panel on COVID-19.

      “Any attempt to deduce severe illness vaccine effectiveness from semi-crude illness rates among the yes or no vaccinated is very, very risky,” he maintained.
      Illustrative: Medical staff in the coronavirus ward of Ziv Medical Center in the northern Israeli city of Safed, on February 4, 2021. (David Cohen/Flash90)

      Infectious diseases doctor Yael Paran told The Times of Israel that she can’t reconcile the figures on serious illness with the much more rosy reality she sees.

      “What we see in our hospital and around the world don’t support this,” she said. “I think the figures are exaggerated.”

      Huppert acknowledged that the statistics have their limitations. “These are early estimations based on small numbers, and there are all kinds of biases in the numbers,” he said. But he insisted that despite the caveats, they still have great relevance.”

      1. David says:

        The whole subject is best described in the article by:
        ‘Any attempt to deduce severe illness vaccine effectiveness from semi-crude illness rates among the yes or no vaccinated is very, very risky’
        ‘there are all kinds of biases in the numbers’.
        We keep coming back to what we know:
        – vaccines are less effective dealing with the new variants (but we don’t know by how much), especially in blocking infections;
        – vaccination lowers disease severity (but not for everyone, and we don’t know by how much);
        More than that, it’s mainly speculation and estimates.

      2. Tony M says:

        Israel has had 862,717 Covid-19 cases or 9.25% of the population.

        When you look at the recent cases in the vaccinated and unvaccinated, you need to determine the levels of cases in each group. For example in the 70-79 age group we have :
        – 92.8% have received 2 doses;
        – 2.6% have received just 1 dose;
        – 4.6% are unvaccinated;

        However, I calculate 25,339 or about 5.9% of this age group have caught Covid-19. These people probably have natural immunity and in total form a larger group than the total unvaccinated. So how are these distributed among the 3 categories above. Have 92.8% gone on to receive 2 doses of vaccine or do they make up the bulk of the people in the unvaccinated/ 1 dose group?

        Any measure of vaccine efficiency will need to separately account for these cases in both the infections and in the relevant population sizes.

        1. theasdgamer says:

          Thanks for a very intelligent comment that doesn’t simply regurgitate talking points.

        2. David says:

          I would also be interested in knowing more about the <5% unvaccinated. Is there some reason they can't be vaccinated? Are they 'on the books' but living overseas?
          Are there any factors involved in the cases of infected and hospitalized vaccinated (immunocompromised, cancer etc.)?

      3. theasdgamer says:

        You can see over and over in the history of science that “experts” don’t believe the data…Galileo’s opponents…Lavoisier’s opponents (including Joseph Priestley, the discoverer of oxygen)…Harlan Bretz’s opponents, who opposed his geological theory on catastrophism…

        “Science progresses one funeral at a time.” — Max Planck

        It’s actually not a problem that experts hold stubbornly to their theories. The problem occurs when communication is stifled and people are silenced.

  29. bacillus says:

    Wouldn’t mild COVID in the fully vaccinated lead to a boost in their protective immunity? i.e. what is the rate of clinical COVID in double vaccinated, breakthrough recovered individuals vs just double vaccinated individuals? Maybe the latter are so well vaccinated against clinical COVID for any statistically meaningful differences with the former to show up unless you took a deeper dive (e.g. maximum viral load, persistence of the virus).

  30. FalconAPK says:

    Surprising what sum has happened since this article was posted. The essential concern is that the Lancet needs to pull out the article as for HCQ not working and having real responses. Turns out the association doing the assessment “Surgisphere” was under solid.

    The quantity of people have passed on or will fail horrendously considering Trump aggravation condition.

    Falcon APK

    1. MetroGnome says:

      CDC used data from a days-long July 4 celebration in Provincetown, MA — legendary for being a party town. A lot of the people were almost certainly engaging in various types of high-risk behavior, fueled by various types of high-risk (and immune system compromising) substances, in very crowded, even intimate, situations over extended periods of time. Shouldn’t findings be replicable, and a population sample be representative, for scientific validity? To generalize from this situation to the everyday encounters most people have indoors seems, to me, specious. Definitely these findings should be noted and reported, but they should be considered preliminary at best.

      As for the increased viral loads found in some of the individuals observed, I share Shane Crotty’s skepticism (from his Twitter post): “Ct and viral load interpretations have been notoriously inaccurate in reports for variants over the past 8 months. Lots of experiment controls have to be in place, so I currently put more weight on other data. It’s 1 unpublished report.”

      Meanwhile, the Kaiser Foundation conducted a survey of the websites of 25 states that reported data on “breakthrough” COVID infections among fully vaccinated individuals. Their findings: “The data reported from these states indicate that breakthrough cases, hospitalizations, and deaths are extremely rare events among those who are fully vaccinated against COVID-19. The rate of breakthrough cases reported among those fully vaccinated is well below 1% in all reporting states, ranging from 0.01% in Connecticut to 0.90% in Oklahoma. The hospitalization rate among fully vaccinated people with COVID-19 ranged from effectively zero (0.00%) in California, Delaware, D.C., Indiana, New Jersey, New Mexico, Vermont, and Virginia to 0.06% in Arkansas. (Note: Hospitalization may or may not have been due to COVID-19.)

      “The rates of death among fully vaccinated people with COVID-19 were even lower, effectively zero (0.00%) in all but two reporting states, Arkansas and Michigan where they were 0.01%. (Note: Deaths may or may not have been due to COVID-19.)”

      All of which leads me to conclude that the CDC’s recent report on the risk of “breakthrough” cases and COVID transmission among the vaccinated (based, as far as I know, solely on the Provincetown incident), as well as their mask mandate ukase, represent a rather panicky over-reaction. Yes, the Delta variant is extremely contagious, and yes, people at high risk, or who regularly encounter high-risk people, should no doubt wear a mask. But we need to do everything we can to encourage vaccine uptake, first and foremost, and what the CDC has done over the past few days, aside from being shoddy science, unfortunately also seems certain to have the unintended consequence of discouraging, rather than encouraging more skeptical and hesitant people to get their shots.

      1. theasdgamer says:

        Problems occur when the percent transmission to the vaccinated is higher than their percent in the population–then you start thinking about ADE.

        We have seen that trend in Israel already. I have seen it in my own back yard–reported by a hospital just last week, but it wasn’t the case before then.

        Now in Massachusetts.

        I suspect that the vaccines’ effectiveness is dwindling at the same time that immune escape is rearing its ugly head. Antibodies may be dwindling and perhaps there weren’t many memory cells created.

        That would account for divergence from earlier data.

        The vaccinated percent hospitalized is increasing, per the CDC. This seems to suggest that antibodies might be failing. Deaths are still low.

        There’s a very human tendency to deny the data, no matter where your beliefs fall. I keep an eye out for conditions that would amount to a black swan that would disprove my working theory. I think ahead of time about stuff like that as a check against falling for the sunk cost fallacy.

        1. David says:

          Do you see any evidence for ADE? I would suspect ADE when the ratio of severe cases (such as hospitalization or deaths) is higher in the vaccinated population than the unvaccinated. I’m not sure if we can compare infection rates, and attribute this to ADE.
          So far, vaccinated people seem to have less severe cases and lower IFR/CFR, than unvaccinated. We have to remember that the vaccinated and unvaccinated do not have the characteristics (in terms of age, health, etc.). While the vaccines seem to be less effective at preventing infection than was previously shown, they still seem to be effective at lowering severe cases (hospitalization and deaths) (,,,,
          Is this due to the antibodies being less effective at binding the new variants, diminishing AB levels, or the higher viral load of the new variants (such as Delta)? The solution would depend on the reason behind this worrying trend.
          The vaccines are less effective (not good) but it’s hard to quantify by how much. I guess the question should be – are they still effective enough?

          As for the famous ‘Provincetown outbreak’, low hospitalization (1.3%) and no deaths among the vaccinated seems to be an overall positive. It’s hard to compare the vaccine effectiveness calculation from different areas or countries (

  31. theasdgamer says:

    “Super antibody” makes sarbecoviruses unlikely to escape the immune system…

  32. Hi .. Maybe the PCR test will be approved, so no need to keep it under EUA any more? Make room for new tests that perhaps will be able to distinguish between flu and covid for clinical use?

    There can be many reasons for withdrawing the PCR EUA. It’s strange that the CDC doesn’t explain further.

    1. David says:

      I think that this is a classical case of not reading the CDC page all the way through and not having a familiarity with GLP – when you finish reading through, you won’t have to ask. Where did you ‘read’ about this notification, and how did they (miss)represent the announcement?

      It should be obvious to anyone reading the line ‘CDC is providing this advance notice for clinical laboratories to have adequate time to select and implement one of the many FDA-authorized alternatives’ that this is only a procedural notification for labs using older methods and that there are lots of approved methods (

  33. NewsView says:

    I am dumbfounded that they are not telling us what the breakthrough infections may reveal about which vaccines are holding up better than others.

    I am equally confused about how we can draw meaningful inferences about vaccine efficacy to protect from breakthrough (or serious) infection when those who had COVID-19 immunity from prior infection were actively advised to go ahead and vaccinate anyhow. Given that COVID-19 had the run of the globe for a year before vaccines rolled out and an unknown percentage were asymptomatic and recovered, theoretically, their resistance against Delta could be propping up the efficacy data. Is anybody attempting to look at breakthrough cases and/or serious post-vaccination infections as it relates to vaccination alone vs. vaccination in concert with naturally-acquired immunity or have the two been hopelessly co-mingled?

    1. Derek Lowe says:

      “What vaccines did people have with breakthrough cases in Minnesota?
      Glad you asked.
      1,626,557 MN got Pfizer – 2,074 breakthroughs (0.13%)
      1,125,919 MN got Moderna – 976 breakthroughs (0.08%)
      266,975 MN are J&J – 813 breakthroughs (0.30%)”

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