This study assessed the primary series of two doses of the Pfizer-BioNTech Covid vaccination effectiveness against infection, hospitalization, and death up to 8 months after vaccination, and also assessed the effectiveness of 3 doses of the vaccine up to 3 months after vaccination.
The majority of the vaccines available for Covid have two doses. People are said to become more capable of resisting the virus after the second dose. But, a recent Kaiser Permanente study, found that one month after a third dose, the effectiveness of the Pfizer-BioNTech Covid vaccine was higher for preventing infection and hospitalization than 2 doses of the vaccine after 1 month.
The study was published in ‘The Lancet Regional Health – Americas’.
“When we looked at the effectiveness of the 2 doses of Pfizer-BioNTech vaccine versus 3 doses, we see a benefit with 3 doses that exceeds that achieved with 2 doses alone,” said Sara Y. Tartof, PhD, an epidemiologist with the Kaiser Permanente Southern California Department of Research & Evaluation and a member of the faculty of the Kaiser Permanente Bernard J. Tyson School of Medicine, both in Pasadena.
This study assessed the primary series of two doses of the Pfizer-BioNTech Covid vaccination effectiveness against infection, hospitalization, and death up to 8 months after vaccination, and also assessed the effectiveness of 3 doses of the vaccine up to 3 months after vaccination.
To assess effectiveness, this research study evaluated electronic health records of 3.1 million members of Kaiser Permanente in Southern California from December 14, 2020, to December 5, 2021.
During the study period, 197,535 (6.3 per cent) patients were infected with SARS-CoV-2, and of those, 15,786 (8 per cent) were admitted to the hospital. During the study period, the predominant variant was delta and not omicron.
