The vaccine developed by American biotech Moderna in partnership with the National Institutes of Health (NIH) triggered a " robust " immune response and prevented replication of the virus in the lungs and noses of monkeys, according to results released Tuesday. It is one of two western vaccines, along with that of the University of Oxford / AstraZeneca, to have started large-scale trials, on thousands of human participants, called phase 3. The government of Donald Trump has invested nearly a billion dollars to support its development.
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Seven of eight monkeys vaccinated in this study and then deliberately exposed to the coronavirus four weeks later no longer had detectable replicating virus in the lungs two days later, and none of the eight had virus in their nose, according to results published by the New England Journal of Medicine. Scientists had previously found that vaccination, in two doses separated by 28 days, not only caused the production of antibodies against the coronavirus, but also T cells essential for the immune response. " This is the first time that an experimental vaccine against Covid-19 tested on non-human primates demonstrates its ability to produce rapid viral control in the upper respiratory tract, " the NIH welcomed in a statement.
Scientists note by comparison that Oxford's vaccine (based on an adenovirus, while Moderna's uses messenger RNA technology) had no effect on the amounts of virus in the noses of monkeys. Reducing the amount of virus in the lungs would make the disease less virulent in the patient, while the reduction in the nose should make a person spread the virus less around them.
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But only the phase 3 trials, in progress, will make it possible to verify whether one and / or the other of the vaccines protects humans. We will compare the rate of contamination in volunteers who received a placebo to those who were actually vaccinated. Results are possible from September for the Oxford / AstraZeneca vaccine, according to the boss of the laboratory, and perhaps from October or November for the American, according to the boss of Moderna.