Episode Details

BNT162b2 vaccine booster dose protection: A nationwide study from Israel https://www.gov.il/BlobFolder/reports/vaccine-efficacy-safety-follow-up-committee/he/files_publications_corona_booster-27082021.pdf Background On July 30, 2021 Third (booster) dose of the Pfizer BNT162b2 Approved in Israel for 60 years or older, who had been fully vaccinated At least five months previously We estimate the reduction in relative risk for confirmed infection and severe COVID-19 Per person-days at risk July 30 and August 22, 2021 Dynamic cohorts Moved from ‘non-booster’ to join the ‘booster’ cohort 12 days later No-booster cohort 4.0 million person- days 3,473 confirmed infections 330 cases of severe COVID-19 Booster cohort 3.4 million person-days 313 confirmed infections 32 cases of severe COVID-19 Twelve days or more after the booster dose we found 9.6 - 11.4 - 13.4 fold decrease in the relative risk of confirmed infection 9.5 - 15.5 fold decrease in the relative risk of severe illness Discussion If waning immunity to Delta is 50% protection against infection at more than 6 months A booster - vaccinated individual susceptible to infection would decrease to 5% relative to unvaccinated Therefore vaccine efficacy for booster-vaccinated individuals to 95% (similar to the original “fresh” vaccine efficacy against the Alpha strain) Our findings give clear indications of the effectiveness of a booster dose even against the currently dominant Delta variant US and UK current thinking https://www.cdc.gov/coronavirus/2019-ncov/vaccines/booster-shot.html https://www.gov.uk/government/groups/joint-committee-on-vaccination-and-immunisation Moderately to severely immunocompromised people

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