(HealthDay News) — The BNT162b2 (Pfizer-BioNTech) vaccine is highly effective against COVID-19-related hospital admission up to six months after full vaccination, according to a study published online Oct. 4 in The Lancet.
Sara Y. Tartof, Ph.D., from Kaiser Permanente Southern California in Pasadena, and colleagues examined overall and variant-specific effectiveness of BNT162b2 against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections and COVID-19-related hospital admissions. Data were included for 3,436,957 individuals between Dec. 14, 2020, and Aug. 8, 2021.
The researchers found that effectiveness against SARS-CoV-2 infections was 73% for fully vaccinated individuals and 90% against COVID-19-related hospital admissions. There was a decline noted in effectiveness against infections, from 88% during the first month after full vaccination to 47% after five months. Vaccine effectiveness against infections of the delta variant was 93% during the first month after full vaccination and decreased to 53% after four months. Effectiveness against other variants declined from 97% during the first month after full vaccination to 67% at four to five months. For all ages, vaccine effectiveness against hospital admissions for infections with the delta variant was high overall up to six months (93%).
“Our study confirms that vaccines are a critical tool for controlling the pandemic and remain highly effective in preventing severe disease and hospitalization, including from the delta and other variants of concern,” Tartof said in a statement. “Protection against infection does decline in the months following a second dose.”
Several authors disclosed financial ties to pharmaceutical companies, including Pfizer, which funded the study.
