According to an American study, the preliminary results of which were published on Wednesday, people who have received the Covid-19 vaccine from Johnson & Johnson have every interest in receiving a booster dose of Moderna or Pfizer. And for good reason, the study reveals antibody levels multiplied by 35 after a booster of Pfizer and by 76 after a booster of Moderna.
US study investigates vaccine mix for booster dose
A US study, funded by the National Institutes of Health (NIH), looked at the vaccine mix for the booster dose. Published this Wednesday, October 13, 2021, the preliminary results of the study show, among other things, that a booster with Moderna or Pfizer would be more effective for vaccinated Johnson & Johnson.
While in France, people who have received a dose of Johnson & Johnson (regardless of their age) can already receive a second dose with a messenger RNA vaccine (from four weeks after the first injection), Americans to them, are not yet allowed to mix vaccines. Therefore, the results of this study were eagerly awaited in the country.
Antibody levels increased 35-fold after Pfizer booster and 76-fold after Moderna booster
To reach their conclusion, the researchers conducted their study on 458 adults vaccinated (with one of the three vaccines authorized in the United States: Pfizer, Moderna or Johnson & Johnson) for at least twelve weeks. The latter were then divided into three groups, themselves divided into three new groups, to receive respectively one of the three vaccines available as a booster dose. In total, the study therefore focused on nine groups made up of 50 people each. Once the groups were done, the scientists were able to analyze the antibody levels of each individual after the injection of a booster dose.
According to the results, the antibody levels of people vaccinated with Johnson & Johnson increased fourfold after a booster dose of the same vaccine, 35-fold after a booster of Pfizer, and 76-fold after a booster of Moderna. In addition, the researchers revealed that the antibody levels of people initially vaccinated with Moderna were each time higher compared to people initially vaccinated with Pfizer or Johnson & Johnson, “ regardless of the vaccine given for the booster dose “. Regardless, the researchers clarified that “no security issues were identified” after the reminders were administered.
A study yet to be peer-reviewed and which has several limitations
If these results give new information to the committee of experts of the United States Medicines Agency (FDA), which is due to study this weekend, the requests for authorization for a booster dose of Moderna and Johnson & Johnson, the The study nevertheless has several limitations. Indeed, the study which has not yet been approved by peers and which included a reduced number of participants, focused on an observation of the antibodies fifteen days after the administration of the booster dose. However, the immune reaction can evolve beyond this period of time. Additionally, the Moderna booster dosage given during the study was 100 micrograms, which is double what the company is actually envisioning for its booster dose.
