"Abstract
Importance: There is limited evidence on the effectiveness of the BNT162b2 vaccine for children, particularly those 5-11 years and after the Omicron variant’s emergence.
Objective: To estimate BNT162b2 vaccine effectiveness against COVID cases and hospitalizations among children 5-11 years and 12-17 years during December, 2021 and January, 2022.
Design: Analyses of cohorts constructed from linked statewide immunization, laboratory testing, and hospitalization databases...
Main outcomes/measures: New laboratory-confirmed COVID-19 cases and hospitalizations. Comparisons were made using the incidence rate ratio (IRR), comparing outcomes by vaccination status, and estimated vaccine effectiveness (VE: 1-[1/IRR]).
Results: From December 13, 2021 to January 30, 2022, among 852,384 fully-vaccinated children 12-17 years and 365,502 children 5-11 years, VE against cases declined from 66% ... to 51% ... for those 12-17 years and from 68% ... to 12% ... for those 5-11 years...
Among children newly fully-vaccinated December 13, 2021 to January 2, 2022, VE against cases within two weeks of full vaccination for children 12-17 years was 76% ... and by 28-34 days it was 56%... For children 5-11, VE against cases declined from 65% ... to 12% ... by 28-34 days.
Conclusions and Relevance: In the Omicron era, the effectiveness against cases of BNT162b2 declined rapidly for children, particularly those 5-11 years."
New Pfizer data kills the case for universal child Covid vaccines, by Jay Bhattacharya
"For older kids [ages 12-17], vaccine efficacy against being infected dropped from 76% in the first two weeks after full inoculation to 46% a month later. For the younger kids [ages 5-11], it dropped from 65% in the first two weeks to negative efficacy: -41% a month later. In other words, the vaccinated young kids were actually more likely to be infected than unvaccinated kids a month and a half after vaccination."
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