Vincent Racaniello (Professor in the Department of Microbiology and Immunology at Columbia University's College of Physicians and Surgeons) wrote a blog in which he states “It’s highly unlikely that vaccination will prevent infection with SARS-CoV-2.“ on virology.ws

For some context the specific claim is that it does not prevent infection long term (i.e. one year after receiving) as antibodies rapidly deplete. Not that it doesn’t prevent infection at all. Here's the quote in larger context for reference, emphasis mine:

It’s highly unlikely that vaccination will prevent infection with SARS-CoV-2. Antibody levels rapidly decline after infection or vaccination, especially in the respiratory mucosa. When a virus enters the nasopharynx of an immune individual, it will encounter little antibody opposition and will initiate an infection. However memory B and T cells will spring into action and within a few days produce virus-specific antibodies and T cells. The antibodies will limit infection while the T cells will clear the virus-infected cells. The result is a mild or asymptomatic infection that likely is not transmitted to others.

The recent observations that vaccination appears to prevent asymptomatic infections is a red herring. These studies are being done soon after vaccination when antibody levels in serum and mucosa are high. If these studies were done a year after immunization, the results would be quite different.

Notable claim as the author is Vincent Racaniello, to take directly from Wikipedia: Vincent R. Racaniello is a Higgins Professor in the Department of Microbiology and Immunology at Columbia University's College of Physicians and Surgeons. He is a co-author of a textbook on virology, Principles of Virology.

Related: Part two of blog post question stems from (In general, a good blog to read, if I may say so without it considered promotion - no affiliation)

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    VTC. There's a lot more detail in that blog post that you'd need to include in your question. Also, by my reading the context has more to do with exposure to variants, then length of time after vaccination or previous infection.
    – LShaver
    Jul 29, 2021 at 14:34
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    @LShaver the sentence directly after the quote is "Antibody levels rapidly decline after infection or vaccination, especially in the respiratory mucosa. When a virus enters the nasopharynx of an immune individual, it will encounter little antibody opposition and will initiate an infection." - how is that not having to do with time after vaccination?
    – TCooper
    Jul 29, 2021 at 15:18
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    Your question says one year later, while the linked blog just says "after." However, the preceding paragraph seems to indicate that the author is talking about exposure to variants. My interpretation is that the author doesn't doubt that the vaccine prevents infection from the variant the vaccine was developed to protect against, and the point isn't about how long it may (or may not) provide such protection, but understanding the mechanism by which it may still prevent severe infection from variants. Whether it's unclear on purpose or accident is, well, unclear.
    – LShaver
    Jul 29, 2021 at 15:25
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    I may edit later if I get a chance. As it stands, I think your title is click-baity, from a click-baity quote in the article that doesn't really get at the author's point, which seems to be that a side effect of the vaccine is activating a T-cell response, and that future vaccines should focus on this, since it's the mechanism by which the vaccines are already protecting from severe infection by variants.
    – LShaver
    Jul 29, 2021 at 15:27
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    There are number of different diseases for which a vaccine is used and where a "booster shot" is needed after some time interval to maintain immunity. Researchers have stated on numerous occasions that they don't know if boosters for COVID are needed, and, if so, at what intervals. This is still a topic of research (and, as such, makes this question an "unresolved current event"). Jul 29, 2021 at 20:31

1 Answer 1


tl;dr; Yes, but that in no way implies the vaccines are ineffective at one year because there are immune responses besides simple antibody count (which is what prevents initial infection).

Yes, BUT (at least referencing the mRNA) vaccines have been shown to be highly effective in preventing severe illness as a result of infection:

The data, involving nearly 12,000 people who have been followed for at least six months after vaccination, also showed the two-dose shot was 100% efficacious in protecting them from severe disease as defined by the U.S. Centers for Disease Control (which means any disease requiring hospitalization, intensive care or a ventilator) and 95% efficacious in protecting against severe disease by the FDA’s broader definition, which includes any respiratory distress or shortness of breath at rest, or oxygen saturation below 93%.

While this study only provides 6 months of information, longer studies on the immunity gained from natural infection, combined with studies on immune response comparisons between natural infection and vaccination, allow for logical deduction/an extrapolation of data sets around the vaccines efficacy at the one-year post-inoculation time frame. Without empirical data over the exact time frame firm statements are hard to make, but given the evidence suggests long term protection well beyond a year at this point, in tandem with the reasons outlined below, I believe the one year time frame is currently safe to discuss in an evidence-backed manner.

Information from related viruses such as SARS-COV1 (immune memory lasting 17 years after initial infection) and immune responses to other pathogens such as the flu implies that even though the vaccine may not prevent an initial infection for a long term after initial inoculation, the vaccines should provide some lasting protection as they produce "memory b" and "memory t" cells, which have been shown to last years, decades, and even lifetimes. This study confirms natural immune responses are sufficient for up to eight months, and with extrapolation of the data sets, a true long term protection from the virus(well over 1 year, unless cell half life suddenly and drastically decreases in an unprecedented manner). Given the vaccines have been shown to induce b and t cells to at least the same degree as natural infection (see also here), it follows there will be a similar long term protection from severe illness.

While the use of naturally occurring protection from those previously infected is a good baseline to help establish long term vaccine efficacy though comparison of early vaccinated vs. recovered patient data and longer term recovered patient data, it should not detract from the apparent value of the previously infected being vaccinated. The patients protection is increased by vaccination, and more homogenous (in sufficient levels of protection) compared to the resulting protection only from natural infection. Although other studies indicate natural protection is sufficient to prevent severe reoccurrences in well over 90% of study participants, as linked above, there are still potential benefits versus new variants to being vaccinated regardless of prior infection. Vaccine efficacy versus new variant strains is still a hotly debated topic, and the information provided regarding the effectiveness against new covid variants is certainly up for debate more so than the efficacy of the vaccines against the initial covid variant. It's important to note the evidence presented here is strictly related to the initial variant as there isn't sufficient data around the new variants at this time - although all preliminary findings show the vaccines offer at least some protection against currently known variants of concern as defined by the WHO. However, the CDC hasn't published as certain of statements on the matter (see last section).

While the vaccine may not prevent another initial infection, it should, in most cases, provide a level of protection adequate to slow or potentially even stop the larger spread of the virus for at least one year after inoculation, with current data suggesting an even longer time frame.

Sources, 1, 2, 3, besides that linked in first word, confirming new initial infections after vaccination(also stating experts confirm it’s not a concern or a knock on vaccine efficacy). Also note the legitimacy of the information from the initial source that raised the question, both in terms of an inability to prevent new infections, but also summarizing most of the information here far more eloquently.

Thanks to @mmmmmm, and @LangLangC for challenging key points and statements made in haste within the answer. More critique / counter points to improve the answer are warmly welcomed.

  • This is the answer I was expecting, as it's my own thoughts on the situation, but I was (and am) hoping others will weigh in to either confirm my research/deductions, or dispute them to make me re-evaluate.
    – TCooper
    Jul 29, 2021 at 21:39
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    Yes but you have not shown any sources saying the protection will not prevent infections a year after taking the vaccine. ie it works well now but will anti-bodies rapidly deplete which is what your question asks
    – mmmmmm
    Jul 29, 2021 at 21:51
  • @mmmmmm I was thinking confirming the source in the question was the source, but good point. I’ll provide sources and details for that as well. Of course happy to hear dissenting opinions as well. Also part of it is an extrapolation from the Times article, in that there were plenty of infections in vaccinated individuals, but no serious illness. - but I’ll be sure to note that along with other sources.
    – TCooper
    Jul 29, 2021 at 21:57
  • 'Leaky vaccines' do not stop the spread. 'Homogenous' is in fact a problem: natural immunity recognizes >1400 viral epitopes, with Abs against the range, 'vaccines' only those few on S. T/B-cells are better & longer lasting than Abs, but those cells also only ever saw S in vacs, and interferon response is altered in infection as well, not in injection. And that's why re-infection is so rare, breakthroughs so common (especially when VacAbs wane and S mutates, like seen in Israel). Unless you can reconcile this latter empirical finding with the above theories, I conclude the theories lose. Jul 30, 2021 at 7:03
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    Pfizer’s original study with 20,000 vaccinations is now about 12 months in the past. I would wonder if these people have been observed in the long term and if any change in their vulnerability would have been noticed.
    – gnasher729
    Aug 2, 2021 at 19:31

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