In people vaccinated with Janssen, antibody levels would increase 4-fold after a booster dose of the same vaccine and 35-fold after a Pfizer booster, and even 76-fold after a Moderna booster.
- In France, just over a million doses of Janssen vaccine have been injected.
- There were no serious side effects from the additional injections and no new symptoms appeared after the participants received the booster shots.
In France, a little over a million cumulative doses of Janssen vaccine have been injected, according to data from CovidTracker. Unlike the others, this vaccine promised to be effective with just one dose. Like the other products, it is subject to a booster dose in order to reinforce and prolong the protection of patients in people over 65, immunocompromised or caregivers. An American study pre-published this Wednesday in the journal medxRiv reveals that this booster dose is much more effective for patients who have received an injection of Janssen if it is carried out with Pfizer or Moderna.
Moderna, the most effective booster dose vaccine
The study involved 458 adults vaccinated with Pfizer, Moderna or Janssen vaccines for at least 12 weeks. Each of these groups was then divided into three, depending on the vaccine used for the booster dose. The nine groups in total therefore consisted of approximately 50 people each. The researchers then analyzed antibody levels 15 days and four weeks after the booster dose was administered.
The results revealed that all the combinations increased antibody levels but to very different levels. In this game, the Moderna vaccine wins the prize for the highest level of antibodies. In patients who received a first dose of Janssen, use of the vaccine developed by Moderna increased antibody levels 76-fold. The Pfizer product multiplied this rate by 35 while those who received the Janssen vaccine twice saw their antibody levels increase fourfold.
No new side effects
Furthermore, the study points out that there were no serious side effects related to the additional injections and no new symptoms appeared after the participants received the booster injections.
“These data suggest that if a vaccine is approved or licensed as a booster, an immune response will be generated regardless of the primary vaccination schedule against Covid-19.concluded the National Institutes of Health (NIH) researchers. Heterologous primary stimulation strategies may offer immunological advantages to optimize the extent and longevity of protection achieved with currently available vaccines.”
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