Johnson & Johnson announced Friday that its vaccine was 66% effective against Covid-19, with a downside: it is less so in South Africa, a country where a variant of the coronavirus suspected of being more transmissible has emerged. is already spreading in around thirty countries.
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The vaccine, which requires only one injection, is 85% effective in preventing severe forms of the disease, according to a major clinical trial, which involved nearly 44,000 people in 80 countries.
"
We are proud to have taken this crucial step
," said Alex Gorsky, CEO of the American firm, specializing in hygiene and pharmaceutical products.
The group has pledged to ship 100 million doses to the United States by the end of June, around 200 million doses to the European Union by the end of the year, with first deliveries in April, and about 200 million doses to developing countries, with first shipments starting after June.
Viral vector
Unlike the vaccines from Pfizer and Moderna, which use the innovative messenger RNA technique, the “
J&J
” vaccine is a “
viral vector
” vaccine
.
These vaccines use another weakly virulent virus as a carrier, transformed to add part of the virus responsible for Covid-19.
The modified virus enters the cells of vaccinated people, which then make a protein typical of SARS-CoV-2, training their immune system to recognize it.
A process that is similar to the vaccines of AstraZeneca, Sputnik.
One important advantage of Johnson & Johnson's single-dose vaccine is that it can be stored at refrigerator temperatures rather than deep freezers, making it much easier to distribute.
Reason for concern
But it also raises a cause for concern: from 72% in the United States, its effectiveness against Covid-19 drops to 57% in South Africa, where a variant suspected of being very contagious of the coronavirus has become the majority.
Numerous mutations of the coronavirus have been observed since its appearance, the vast majority without consequence.
However, some may give it an advantage for its survival, including greater transmissibility.
This is the case with the so-called British mutation and scientists suspect that the South African and Brazilian variants are also likely to be more contagious.
Johnson & Johnson should apply for an emergency distribution authorization in the United States as early as next week, which would allow it to become the third vaccine in circulation in the country, alongside those of Moderna, and Pfizer-BioNTech.
Pfizer and BioNTech laboratories announced Thursday that their vaccine retained the vast majority of its effectiveness against the main mutations of the English and South African variants of the coronavirus causing Covid-19.
The American biotechnology company Moderna had so far indicated that its vaccine against Covid-19 remained effective in particular against the British variant, but that a reduction in protection against the South African variant had been observed.
The potential addition of a new vaccine comes as the United States seeks to accelerate its rate of immunization, the target of new President Joe Biden having been set at 1.5 million doses injected per day.
