Incidence of Severe COVID-19 Illness Following Vaccination and Booster With BNT162b2, mRNA-1273, and Ad26.COV2.S Vaccines
JD Kelley et al, JAMA September 26, 2022
This retrospective cohort study included 1?610?719 participants receiving care at Veterans Health Administration facilities, followed up for 24 weeks (July 1, 2021, to May 30, 2022) after completing a COVID-19 vaccination series and booster. Overall, the incidence of hospitalization with COVID-19 pneumonia or death was 8.9 per 10?000 persons. In a US cohort, there was a low incidence of hospitalization with COVID-19 pneumonia or death following vaccination and booster during a period of Delta and Omicron variant predominance.
Long-term Protection Associated With COVID-19 Vaccination and Prior Infection
MM Tenforde et al, JAMA, September 26, 2022
Developing the best strategies to reduce the morbidity and mortality associated with future COVID-19 surges warrants a strategic approach to monitor vaccine effectiveness. Monitoring will require complementary surveillance systems that can generate timely vaccine effectiveness estimates with accuracy and precision to guide policies and research.
Association of Primary and Booster Vaccination and Prior Infection With SARS-CoV-2 Infection and Severe COVID-19 Outcomes
DY Lin et al, JAMA, September 26, 2022
In a cohort study of 10.6 million North Carolina residents from March 2020 to June 2022, receipt of a primary COVID-19 vaccine series compared with being unvaccinated, receipt of a booster compared with primary vaccination, and prior SARS-CoV-2 infection compared with no prior infection were all significantly associated with lower risk of SARS-CoV-2 infection and resulting hospitalization and death. The estimates for the associated protection decreased over time, especially for the outcome of infection, and varied by type of circulating variant.
Estimated Effectiveness of COVID-19 Vaccines Against Omicron or Delta Symptomatic Infection and Severe Outcomes
SA Buchan et al, JAMA Network Open, September 23, 2022
In this test-negative case-control study of 134?435 adults in Ontario, Canada, the estimated effectiveness of 2 doses of COVID-19 vaccine was high against symptomatic Delta infection and severe outcomes and was lower against symptomatic Omicron infection. After a third dose, estimated vaccine effectiveness against Omicron was 61% for symptomatic infection and 95% for severe outcomes.