The effectiveness of the Pfizer / BioNTech COVID-19 vaccine drops to 47% six months after the second dose, from 88%, Reuters reported Monday, citing the latest study results.
Analysis of the collected data also showed that the effectiveness of the vaccine in preventing death from infection and the effectiveness of protection against the severe course of COVID-19, requiring hospitalization, remains at a high level – 90%. at least six months, also in case of infection with the Delta variant.
Researchers from Pfizer and Kaiser Permanente analyzed electronic health records of approximately 3.4 million people between December 2020, when the vaccine became available, to August 2021.
According to experts, the decrease in the effectiveness of the vaccine is associated with a weakening of the effectiveness of the drug, and not with the greater infectivity and aggressiveness of subsequent mutations of the coronavirus.
“Our studies of different variants of the virus clearly show that the Pfizer / BioNTech vaccine is effective against all existing strains, including Delta,” said Luis Jodar, Pfizer’s medical director.
The effectiveness of the drug against the Delta variant is 93 percent, after the first month, and after four months it drops to 53 percent. In the case of other variants of the coronavirus, the effectiveness of the vaccine is reduced to 67%. from the initial 97 percent
The FDA has authorized the use of a third booster dose of Pfizer / BioNTech vaccine in seniors and people at high risk of SARS-CoV-2 infection. A population-wide solution requires supplementing the available scientific evidence.