A new study has found a gradual increase in the risk of COVID-19 infection from 90 days after receiving a second dose of the Pfizer-BioNTech vaccine.
Results confirm that protection wanes with time and suggest a third (booster) dose might be warranted.
The findings of the study were published in the journal 'BMJ'.
The study was carried out by the Research Institute of Leumit Health Services in Israel. Israel was one of the first countries to roll out a large scale covid-19 vaccination campaign in December 2020, but it has seen a resurgence of infections since June 2021.
The findings confirm that the Pfizer-BioNTech vaccine provided excellent protection in the initial weeks after vaccination, but suggest that protection wanes for some individuals with time.
Across the world, large scale covid-19 vaccination campaigns are helping to control the spread of the virus, but even in countries with high vaccination rates, breakthrough infections can occur, which scientists think is due to a gradual loss of immunity over time.
Examining the time elapsed since vaccination and the risk of infection could provide important clues about the need for a third injection and its preferred timing. -- ANI