ABSTRACT

Background BNT162b2 is a lipid nanoparticle-formulated, nucleoside-modified RNA vaccine encoding a prefusion-stabilized, membrane-anchored SARS-CoV-2 full-length spike protein. BNT162b2 is highly efficacious against COVID-19 and is currently authorized for emergency use or conditional approval worldwide. At the time of authorization, data beyond 2 months post-vaccination were unavailable.

Methods In an ongoing, placebo-controlled, observer-blinded, multinational, pivotal efficacy study, 44,165 ≥16-year-old participants and 2,264 12-15-year-old participants were randomized to receive 2 doses, 21 days apart, of 30 µg BNT162b2 or placebo. Study endpoints reported here are vaccine efficacy (VE) against laboratory-confirmed COVID-19 and safety data, both up to 6 months post-vaccination.

Results BNT162b2 continued to be safe and well tolerated. Few participants had adverse events leading to study withdrawal. VE against COVID-19 was 91% (95% CI 89.0-93.2) through up to 6 months of follow-up, among evaluable participants and irrespective of previous SARS-CoV-2 infection. VE of 86%-100% was seen across countries and in populations with diverse characteristics of age, sex, race/ethnicity, and COVID-19 risk factors in participants without evidence of previous SARS-CoV-2 infection. VE against severe disease was 97% (95% CI 80.3−99.9). In South Africa, where the SARS-CoV-2 variant of concern, B.1.351 (beta), was predominant, 100% (95% CI 53.5, 100.0) VE was observed.

Conclusion With up to 6 months of follow-up and despite a gradually declining trend in vaccine efficacy, BNT162b2 had a favorable safety profile and was highly efficacious in preventing COVID-19. (ClinicalTrials.gov number, NCT04368728)

doi: https://doi.org/10.1101/2021.07.28.21261159

Data from Pfizer shows that the third dose of the company’s COVID vaccine can increase antibodies to fight the Delta variant 11-fold in people 65 to 85

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  • Efficacy of Pfizer/BioNTech Covid vaccine slips to 84% after six months, data show – STAT
    • he efficacy of the Covid-19 vaccine developed by Pfizer and BioNTech fell from 96% to 84% over six months, according to data released Wednesday, a decline that could fuel Pfizer’s case that a third dose will eventually be required. The data, released in a preprint that has not been reviewed by outside scientists, suggest the vaccine was 91% effective overall at preventing Covid-19 over the course of six months. In the ongoing study, which enrolled more than 44,000 volunteers, the vaccine’s efficacy in preventing any Covid-19 infection that causes even minor symptoms appeared to decline by an average of 6% every two months after administration. It peaked at more than 96% within two months of vaccination and slipped to 84% after six months.
    • Against severe disease, which includes people with low blood oxygen levels or who are hospitalized, the overall efficacy of the vaccine was 97%.
    • To Paul Offit, a pediatrician and vaccine expert at Children’s Hospital of Philadelphia, the results are “very reassuring.” The potential need for booster shots is tied to the number of fully vaccinated people who develop severe disease, Offit said. Of the more than 23,000 volunteers who received the vaccine, only one came down with severe Covid-19 within six months, suggesting two doses of Pfizer’s vaccine offers adequate protection, he said.
    • While the data suggest Pfizer and BioNTech’s vaccine provides lasting protection against the worst symptoms of Covid-19, the paper leaves open the possibility that booster doses will eventually be necessary to curtail infection. If the vaccine’s efficacy continues to decline at the rate observed in the paper, it would fall below the 50% threshold — a benchmark for vaccine utility — within 18 months of vaccination. That would support Pfizer’s contention that two doses of the vaccine won’t be enough to provide long-term protection. Federal authorities have maintained that people who have been fully vaccinated don’t need booster doses yet but that they are continuing to look at new data.
  • Third dose of Pfizer’s Covid vaccine boosts immunity against the Indian ‘Delta’ variant and can trigger an 11-fold spike in antibodies, data suggests – DailyMail
  • ALL over-50s will get Covid booster shots by autumn: People who got AstraZeneca ‘are set to be given a Pfizer jab’ in new vaccine drive because it is more effective against Indian variant – DailyMail

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