Fri. Nov 18th, 2022

Researchers in Australia carried out a study that suggests the second booster dose of the Pfizer-BioNTech vaccine may not increase vaccine efficacy against Covid-19.
The findings of the study indicated that one dose of the vaccine could be sufficient in providing a robust immune response 11 days post-vaccination.
The study Reanalysis of the Pfizer mRNA BNT162b2 SARS-CoV-2 vaccine data fails to find any increased efficacy following the second boost:
The study was published in the preprint server medRxiv* server.
Study design
For the study, the researchers reexamined Pfizer-BioNTech phase III trial data from day 1 to 111 in the placebo and experimental groups.
They studied the efficacy of vaccination from day 11 to day 28 and compared the efficacy of the second vaccine dose delivered on day 28 up to day 111.
The findings demonstrated that the Pfizer-BioNTech mRNA vaccine provided a robust protective immune response 11 days after the first vaccination dose. They also found that the second vaccination did not help to increase efficacy.
Specifically, the first vaccine dose helped develop detectable neutralizing antibodies before the second dose.