COVID-19 Vaccines Probably Prevent PASC (long COVID-19) — Deplatform Disease

  1. There’s this summary of the indirect effects observed with COVID-19 vaccines which discusses some of the data showing they can prevent infection.
  2. This study found that 14 days after the second dose of an mRNA vaccine, the risk of a positive PCR was 90% lower than for an unvaccinated individual.
  3. The prevention of infection is known as sterilizing immunity and it is a process mediated by antibodies. In Pfizer’s recent trial of those aged 12–15 years, the geometric mean titers (GMTs) of antibodies were even higher than in the 16–25 year-old group. These titers were taken from plasma though, and it is mucosal antibodies within the respiratory tract, especially the upper respiratory tract, which would mediate prevention of SARS-CoV-2 infection- but given the data that infection risk is reduced in adults, and that at least some of the antibodies from plasma (though notably NOT IgA) are transported to the mucosa, it is reasonable to presume that the effects of this parenteral vaccine extend to children at least as well.
  4. The SIREN study of UK healthcare workers confirmed that the Pfizer vaccine is able to reduce the risk of asymptomatic infection by 85% 7+ days after the second dose.
  5. In a nationwide study in Israel, the Pfizer vaccine was able to reduce asymptomatic infection by 90% 7 days after dose 2.
  6. A study of Mayo Clinic patients found that 10 days after 1 dose of mRNA vaccination, the risk of a positive PCR was reduced by about 80%.
  7. Johnson and Johnson/Janssen’s pre-licensure Phase 3 trial measured an efficacy of 65% against asymptomatic infection.
  1. This study showed that for every 20% of the population that is vaccinated, the risk of an unvaccinated person having a positive PCR is halved.
  2. This preprint showed that vaccination of healthcare workers reduced their household’s risk of developing COVID-19 and needing hospitalization by about 30%, and 54% if they had 2 doses.
  3. Another study in England found that the likelihood of household transmission is 40–50% lower for households in which the index cases are vaccinated 21 days or more prior to testing positive (compared to no vaccination), with similar effects for both ChAdOx1 nCoV-19 and BNT162b2 vaccines; however most individuals in the study received a single dose of vaccine.




I write about vaccines here. You can find me on Twitter @enirenberg and at (where I publish the same content without a paywall)

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Edward Nirenberg

Edward Nirenberg

I write about vaccines here. You can find me on Twitter @enirenberg and at (where I publish the same content without a paywall)

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