“Vaccination works”: US CDC announces its effectiveness against severe forms of 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 Delta has become the main strain of virus in the United States, US health officials said on Friday. Data from three articles published by the prevention and disease control (CDC for Centers for Disease Control and Prevention), the country’s main federal public health agency, unanimously underline the continued effectiveness of vaccines anti-Covid against severe forms virus.

This announcement comes the day after the unveiling of President Joe Biden’s new muscular strategy to overcome Covid-19, which notably includes an executive order requiring employees of large American companies to be vaccinated or take a blood test. screening weekly.

Hundreds of thousands of cases studied

« As we have shown, study after study, the vaccination walk “, Insisted the director of the CDC, Rochelle Walenksy, during a press conference. The first study analyzed hundreds of thousands of cases of Covid-19 in 13 US jurisdictions over the period April 4 to June 19, before the Delta proliferated, and compared them to cases of contaminations from June 20 to July 17. Between these two periods, the risk of a fully vaccinated person being infected with Covid-19 compared to a unvaccinated person increased slightly from 11.1 times lower risk of being infected to 4.5 times. Protection against hospitalization and death remained stable, but declined more for people 65 years of age and older than for younger groups of individuals.

Health authorities are assessing the need fora third dose, and seniors are likely to be the first to receive it when the Biden administration launches its recall campaign on September 20.

One of the studies, which analyzed the effectiveness of different vaccines between June and August in more than 400 hospitals and health centers, determined that the serum from Moderna was the most efficient against hospitalizations (95%), than that of Pfizer (80%), and that of Johnson & Johnson (60%).

The reasons why Moderna’s vaccine appears to confer higher protection than Pfizer when the Delta variant became the main strain of the virus is not entirely clear. It could be related to its higher dosage 100 micrograms versus 30 micrograms, or the longer interval between the first and second injection (four weeks versus three for the Pfizer), which could create a immune response stronger.