The effectiveness of the Pfizer-BioNTech vaccine against hospitalizations for Covid-19 drops "significantly" after four months from the second dose.
The data comes from the United States: it was released by the Center for Disease Control and Prevention (Cdc) shortly before the FDA committee of experts expresses its opinion on the third dose, which at the moment in the US is only recommended for over 65s and individuals. at high risk, and not earlier than six months after the second inoculation.
According to CDC Pfizer is 91% effective in preventing hospitalizations up to 4 months after the second dose, then the effectiveness drops to 77%.
The situation is different for Moderna, which remains effective against hospitalizations even after four months. According to the CDC study, the effectiveness of Moderna after 120 days remains almost identical, passing from 93 to 92%.
The study is based on the analysis of 3,700 adults hospitalized in the United States between March and August.
For Johnson & Johnson, however, there are no comparable data: the sample examined did not include enough people who had received the only J&J dose.
The data from the CDC, the New York Times points out, contrast with other studies according to which the efficacy of the Pfizer vaccine against hospitalizations remains above 90% despite the Delta variant.
(Unioneonline / L)