After the announcement on Monday of Jean Castex’s positive Coronavirus test, reactions on social networks were not long in coming. Many Internet users, mostly opposed to the vaccine or to a health pass deemed to be liberticidal, have denounced on Twitter “the proof” of the ineffectiveness of the injections, since the Prime Minister was vaccinated. “The vaccine did not protect him …” All vaccinated, all protected “, this slogan is not true … So many lies”, reacted one of them on Twitter, whose message was retweeted since then, more than 5,700 times.
An opinion shared by the Carton Jaune collective, which presents itself as a collective of yellow vests. “Jean Castex is positive for the Covid and is isolating himself. However, he has the #PassSanitaire and 2 doses of vaccine… Proof that this health pass and this vaccination do not protect or prevent catching this disease, and encourage more contacts. The Pass puts us in danger! “, Estimated the group on its Twitter account. On the political side, the president of the UPR party François Asselineau, who has beaten the pavement several times in recent months to denounce “the health dictatorship”, rushed into the breach on Monday evening, questioning the “effectiveness” of the injections .
A vaccine 90% effective against severe forms
Except that, as epidemiologists have repeated since the start of the vaccine campaign against Covid-19, vaccination does not prevent having the coronavirus. “Vaccines generally protect more effectively and more durably against the risk of serious disease than against the risk of infection,” explains Catherine Hill, epidemiologist at the Institut Gustave-Roussy in Villejuif. The contamination of the Prime Minister despite his two doses of vaccine is therefore nothing abnormal, she emphasizes.
“The effectiveness of the vaccine is 90% against severe forms, but only about 50% against infection,” says Dominique Costagliola, epidemiologist and director of research at Inserm.
The effectiveness of the vaccine is not the same depending on the risks
Since the start of the epidemic and the vaccination campaign, epidemiologists have recalled that the vaccines developed to date cannot completely prevent the circulation of the coronavirus. The lack of 100% efficacy of vaccines is also recognized by the manufacturers themselves and by governments, who insist on the importance of barrier gestures, even in people who have been vaccinated.
“The effectiveness of the vaccine is not the same depending on the risk that we are trying to reduce,” explains Catherine Hill. There is an effectiveness “to avoid being infected”, another “to avoid having a symptomatic disease”, yet another “to avoid going to intensive care”. “These are not the same figures, it depends on the criterion. Right now in France, the vast majority of infections, especially serious ones, occur in unvaccinated people, ”she notes. “In this context, the urgency is to improve vaccination coverage to reach unvaccinated people over the age of twelve”.
Pointed out by their detractors, the serious adverse effects of anti-Covid vaccines remain rare and monitored by pharmacovigilance agencies which have updated the list of side effects on several occasions.