London, Aug 25 (EFE).- The level of protection offered by the Pfizer and AstraZeneca vaccines against symptomatic Covid-19 wanes by six months, according to a British study Wednesday.
An investigation by Zoe Covid said the level of protection offered by a full course of the Pfizer/BioNTech vaccine dropped from 88% to 75% at the fifth or sixth-month mark while AstraZeneca fell from 77% to 67%.
The real-world study looked at over a million positive PCR results from fully vaccinated people between May and June.
Experts said that in the worst case scenario the level of vaccine protection could drop to 50% for health workers and older people — the first groups to be vaccinated — by winter this year.
The study comes at a time when rich countries with advanced vaccine rollouts, such as Israel and the United States, are offering booster jabs to keep immunity levels up.
The World Health Organization has criticized such moves, saying priority should be given to achieving vaccine equity in developing countries. EFE