No offense to antivax, Covid-19 vaccines are actually effective against the Delta variant. Fully vaccinated people are 11 times less likely to die from Covid-19 and 10 times less likely to be hospitalized since the contagious variant became the main strain of the virus in the United States, authorities announced on Friday (September 10th). The
Data from three articles published by the Centers for Disease Control and Prevention (CDC), the country’s main federal public health agency, unanimously underline the continuing effectiveness of vaccines against severe forms of the virus.
This announcement comes the day after the unveiling of President Joe Biden’s new muscle strategy for dealing with the pandemic. In particular, a decree requires employees of major US companies to be vaccinated or to undergo a weekly screening test.
“As we have shown, study after study, vaccination works”, insisted the director of the CDC, Rochelle Walenksy, during a press conference. The first study analyzed hundreds of thousands of Covid-19 cases in 13 U.S. jurisdictions between April 4 and June 19, before the Delta multiplied, and compared them to cases from June 20 to June 17. July.
Moderna significantly more effective
Between these two periods, the risk of infection of a fully vaccinated person with Covid-19 compared with an unvaccinated person increased slightly, from 11.1 times less likely to be infected to 4.5 times. Hospitalization and death protection remained stable, but decreased more for people 65 and older than for younger groups.
Health officials are currently assessing the need for a third tranche, and the elderly are likely to be the first to receive it when the Biden government launches a recall campaign on September 20th.
One study, which looked at the effectiveness of different vaccines between June and August in more than 400 hospitals and health centers, found that Moderna serum was the most effective treatment (95%) before Pfizer (80%). ), and that of Johnson & Johnson (60%).
It is not entirely clear why the Moderna vaccine appeared to provide higher protection than the Pfizer when the Delta variant became the main strain of the virus. This could be related to a higher dose of 100 micrograms versus 30 micrograms, or the longer interval between the first and second injections (four weeks versus three for Pfizer), which could elicit a stronger immune response.