PROTECTION against Covid-19 offered by two doses of the Pfizer/BioNTech and Oxford/AstraZeneca coronavirus vaccines begins to fade within six months, underscoring the need for booster shots, according to researchers in Britain.
After five to six months, the effectiveness of the Pfizer jab at preventing infection in the month after the second dose fell from 88% to 74%, an analysis of data collected in Britain’s ZOE Covid study showed.
For the AstraZeneca vaccine, effectiveness fell from 77% to 67% after four to five months.
It’s bringing into focus this need for some action. We can’t just sit by and see the protectiveness slowly waning whilst cases are still high and the chance of infection is still high as well.Tim Spector, principal investigator, ZOE Covid study
The study was based on data from more than 1.2-million test results.
Previous analysis of data has suggested vaccines provide protection for at least six months.
“It’s bringing into focus this need for some action. We can’t just sit by and see the protectiveness slowly waning whilst cases are still high and the chance of infection is still high as well,” Tim Spector, principal investigator of the ZOE Covid study, said.
Britain is starting to plan for a Covid-19 vaccine booster campaign later this year after top vaccine advisers said it might be necessary to give third shots to the elderly and most vulnerable from September.