Over 189,000 people have been vaccinated against Covid-19 in France since late December. In order to catch other countries up, the French government has announced people aged 75+ can get vaccinated starting January 18th. Another statement? Waiting up to six weeks before injecting the second dose of the Covid vaccine, instead of the three weeks recommended.
A decision that does not convince everyone. Academy of Medicine member Yves Buisson fears this extended gap between the two doses of the vaccine could lead to mutations of the virus. By extending the gab between the two doses of vaccines the virus is “likely to mutate” the professor said on January 12 on France Info.
Although Yves Buisson agrees to say that “extending the gab between the two injections” enables to “increase the number of people who get the first dose of vaccine”, yet, he expresses “reservations” as for the new gab between the two injections. “When the vaccine requires two injections, the gap between the two injections is set by the marketing authorization, 21 days for the Pfizer vaccine, 28 days for the Moderna vaccine” he said, before adding that the second shot “will be a booster of the same quality”.
But Yves Buisson intends to warn against the gap between the first and the second shot. “Immunity is building up during this gap. The first antibodies appear after two to three weeks. The gap between the two shots is a gap people are barely immunized”. Therefore “the risk of being infected during this period between the two shots is a high risk and infection occurring during this period can end up very harmful” the professor explained.
Thus, “in a population that is very weakly immunized, waiting for the second shot, if infection occurs, mutations are likely to happen. Mutations likely to occur during this gap are mutations that might resist to antibodies entailed by vaccine” he said on France Info.
According to Yves Buisson, in order to avoid “theoretical risks”, complying with the marketing authorization rules is better.