Covid: a 3rd dose of Moderna vaccine to be working against variants, a study found

Published by Laurent P. · Published on 6 May 2021 at 16h01
Is Moderna’s Covid vaccine effective against Brazilian and South African variants after a third dose? This is what the American laboratory found this Wednesday May 5, releasing the preliminary and encouraging results of phase 2 of their clinical trial on the matter.

Are Covid variants soon to be a bad memory? Moderna laboratory believes so and releases this Wednesday May 5 the preliminary results of the phase 2 of the clinical trial aiming at showing a third dose of their mRNA vaccine is effective against all strains of the virus known to date. And these results are rather encouraging: it seems that two weeks after injection, this booster shot increased “neutralizing antibody titer responses against SARS-CoV-2” in one’s body, able to attack the standard virus, as well as “two variants of concern”, namely the Brazilian and the South African variants.

Because this is what was lacking to the vaccines currently marketed: two injections were not enough to stop variants, as – after other clinical trials on the matter – they required a larger quantity of antibodies to be eliminated from one’s body. It seems then a third dose has an impact on the virus strains, while waiting for the vaccine to be modified and adapted to mutations. “We are encouraged by these new data, which reinforce our confidence that our booster strategy should be protective against these newly detected variants”, Stéphane Bancel, Chief Executive Officer of Moderna, said in a release.

What was the second phase of this clinical trial consisted in? It included 40 people who have been given two doses of Moderna vaccine already, and divided into three groups to test three strategies, injected six to eight months later: the first one has been given a third dose of the standard vaccine, the second a specially created formula to fight against the SA variant, and the third group a dose combining the standard vaccine and the specific formula. And results are clear: whether it is the first or second group (results for the third group are not available yet), the level of antibodies “increased to levels similar to or higher than the previously reported peak titers”.

The laboratory also states that between the classic dose and the variant-aiming formula, the formula ended up more effective. As for adverse effects, Moderna also explains in the release these third doses “were generally well tolerated”, with common adverse effects such as injection site pain, fatigue or headaches. According to Bancel, this is a success and Modernawill continue to make as many updates to our Covid-19 vaccine as necessary to control the pandemic”.

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