Covid-19: will a fourth dose of vaccine be needed?

Solène Leroux 3:22 p.m., December 8, 2021

INTERVIEW

"We may need a fourth dose at some point."

While the campaign for the third dose of the anti-Covid vaccine began a few weeks ago, the statement by Jean-François Delfraissy, president of the Scientific Council, did not go unnoticed.

The epidemiologist Didier Pittet shares his opinion and remains just as cautious.

"What Jean-François Delfraissy said was that we might need it one day."

He was the guest of Romain Desarbres in Europe Midi on Wednesday.

"In the meantime, I think we have to go to the booster dose, the one that is also called the third dose," he said.

The third dose is "fundamentally important"

According to Didier Pittet, this (third) dose is "fundamentally important", and it is necessary to continue to respect "as well as possible the barrier measures, the instructions which are recommended to fight against the Delta variant and against the impact of this fifth wave. ". "The Covid will be part of what is called our microbiome," then explained the head of the infection control service at the Geneva University Hospitals. "We will live with this virus as we live with the other four very large families of coronaviruses, with whom we have lived for hundreds of years." And to affirm "that one day, it will simply be one of the little colds that we have in the fall, when we go to see our little children" for example.

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The fourth dose, "we're not there yet"

Without rejecting the possibility of a fourth dose, the professor warns: "We are not there yet", recalling that "the overall immunity in the population is still insufficient", and especially "because the coverage vaccine must still be improved, it must include a booster dose ".

He does not exclude that a fourth dose is necessary, but specifies that "it will depend on the evolution of the pandemic" and that "nobody can say it even today". 

Didier Pittet said Wednesday in Europe Midi the effectiveness of vaccines against the Omicron variant. The World Health Organization is reassuring and believes that there is "no reason to doubt that current vaccines protect". When judging the dangerousness of a variant, there are three elements to take into account according to him: first the transmission capacity, i.e. contagion, then the capacity to cause serious infections. and therefore hospitalizations and finally the ability to escape natural or acquired immunity with the vaccine, explains the professor.

If the Omicron variant is more contagious than previous variants, "according to preliminary data, it would be less capable of causing serious infections", adds Professor Didier Pittet.

Cautious, but reassuring news.