Even in the event of infection with the Omicron variant, the vaccines reduce the risk of hospitalization, and the third dose further reinforces the level of protection.
- The appearance of new variants is suspected of reducing vaccine efficacy.
- The Omicron variant first appeared in South Africa in November 2021.
- The study focused on RNA vaccines from Pfizer-BioNtech and Moderna.
Faced with new variants, the scientific community is concerned. Are the various vaccines developed to offer protection against SARS-CoV-2 still effective? The answer is yes, according to a double study American, carried out by the Centers for Disease Prevention and Control (CDC). Its authors note that vaccination protects against severe forms, even against the Omicron variant.
Confirmed efficacy against the Delta variant
This work was performed between August 26, 2021 and January 5, 2022, in ten US states. Scientists analyzed data associated with more than 300,000 emergency room visits in these regions. First, they observed the effects of the vaccines on the Delta variant, which was dominant at the time of the study. According to their conclusions, its effectiveness in preventing hospitalizations is 90% between 14 and 179 days after the second dose. After 180 days, it decreases and reaches 81%. But the third dose makes it possible to reinforce it: in the 14 days which follow this injection, the level of protection against hospitalizations goes up to 94%.
What protection against Omicron?
Secondly, the researchers wondered about the effectiveness of the different serums against the Omicron variant, considered to be dominant in Europe, since Friday 21 January. According to the conclusions of American scientists, the vaccine protects 81% against hospitalizations, between 14 and 179 days after the second dose. This level of protection drops to 57% after 180 days, but the third dose achieves 90%, 14 days after the injection. “The value of the third dose of an mRNA vaccine is significant because two doses were only 38% effective in protecting against Omicron-related ER visits, specify the authors, and only 57% effective in protecting against hospitalizations related to the Omicr variantwe.”
A call for vaccination
Shaun Grannis, lead author of this study, draws two conclusions from his research: “Our results provide important evidence that boosters are highly effective and that those who are unvaccinated are at significantly higher risk of more severe consequences from Covid-19. and should be vaccinated as soon as possible.“ With his team, they could not measure the effect of vaccines on the risk of death linked to Omicron, because the recording of certain data was delayed. But the figures are already available for the Delta variant: unvaccinated people, whose data were observed during the study, were 16 times more likely to die, compared to participants who received both doses, and 50 times more , compared to those who received their third dose of vaccine.
