Slightly more effective than Pfizer, the Moderna vaccine takes its revenge

11:50 p.m., April 9, 2022

When it comes to vaccines, too, appearances are deceptive. While Pfizer-BioNTech’s serum is often preferred over Moderna’s, the unloved is ” the best “. “Clinical trials have been done with different methodologies so we cannot compare them very rigorously but, in real life, the studies show a slight superiority”summarizes the professor of infectiology Élisabeth Bouvet, president of the technical commission for vaccinations of the High Authority for Health.

What do these works say? According to a February presentation by the US Centers for Disease Control and Prevention, two injections of Moderna prevent hospitalizations (slightly) better than Pfizer in the six months following the second dose, although the results are excellent in two cases (92% versus 87%). These figures are consistent with a dozen comparative studies published in scientific journals. One of them, published in December 2021 in the New England Journal of Medicine (NEJM), shows that a dose of Moderna protects better against severe forms but also against infections. Efficacy data provided by health agencies around the world logically yields similar results.

More mild side effects

Why don’t Moderna and Pfizer, based on messenger RNA platforms, have identical efficacy? Because of their “differences”, believe the authors of the NEJM study. By talking about “twin vaccines”we had notably forgotten that the Moderna vaccine was three times more dosed in the first injection and that the interval between the first and second dose was one week longer. “There is certainly a dose effect and we know that spacing out the injections can increase the quality of the immune response”decodes Professor Bouvet.

Read also – Covid-19: why France is behind in the battle for ventilation

But these differences are also flaws, which have fueled the poorer reputation of Moderna’s product. The latter gives more mild side effects (fever, pain at the injection site) and a slight increased risk of myocarditis has been observed in young men. Hence Elisabeth Bouvet’s caution in formulating her message to the general public: “There is a small superiority of Moderna but especially in older and at-risk populations. »

Leave a Comment