Should you be vaccinated against covid-19 with two different vaccines? This is what suggests a study published last week in the prestigious scientific journal Nature. Among the researchers who participated in it, several are affiliated with the Faculty of Medicine of Saint-Étienne: Bruno Pozzetto, Melyssa Yaugel-Novoa, Stéphane Paul and Thomas Bourlet.
12,000 caregivers from Lyon hospitals
For their study, they used caregivers from Lyon hospitals. On the one hand, 10,000 vaccinated with two doses of Pfizer Bio-NTech. On the other hand, 2,500 vaccinated with one dose of Astra Zeneca and one dose of Pfizer Nio-NTech.
Two weeks after the injections 80% of caregivers vaccinated with two doses of Pfizer had contracted covid-19. In the cohort vaccinated with a first dose of Astra Zeneca, they were only one in ten. We would therefore be better protected with two different doses of vaccine, Astra Zeneca and Pfizer, than with two doses of Pfizer.
It was a success that surprised us ourselves – Bruno Pozzetto, virologist in Saint-Étienne
“It was a success that surprised us ourselves,” explains Bruno Pozzetto, virologist and head of the infectious agents and hygiene department of the Saint Etienne University Hospital. The study was submitted for the first time in early July to the journal Nature. “They asked us to prove things. The heterologous group [dont les membres ont reçu deux doses de vaccin différentes] was slightly younger so they asked us to make a correction for age but despite this correction the difference is still very clear. “
The study is freshly published, but Bruno Pozzetto hopes it will help guide vaccine policies in the face of covid-19. “If you stimulate the immune system through various approaches, you boost it better than when you just use the same vaccine over and over again.”