A total of 10,262 contaminations were reported two weeks or more after the injection of the second dose or the single dose of vaccines authorized by the United States Medicines Agency (FDA), i.e. Pfizer, Moderna and Johnson & Johnson.
About 0.01% of people fully vaccinated against Covid-19 between January and April were subsequently infected with the virus, according to a US government study published on Tuesday, confirming the very high effectiveness of the vaccines .
The study looks at the 101 million people who were fully vaccinated in the United States between January 1 and April 30.
Among these infections, 6,446 or 63% of cases involved women, and the median age of patients was 58 years. 2,725 of those infected were asymptomatic, 706 had to be hospitalized and 132 died for reasons related to Covid-19.
Overall, 0.01% of fully vaccinated people were nonetheless infected with the virus, 0.0007% of them were hospitalized, and 0.0001% died.
According to the CDC, the number of infections after vaccination is certainly higher, with asymptomatic cases more often going undiagnosed.
In 5% of the cases of infections, the genome of the virus could be sequenced, showing that the main variant causing the infections was the one first identified in the United Kingdom, B.1.1.7.
The study was conducted when the United States was facing an outbreak of contaminations, with nearly 355,000 cases detected in the last week of April, according to the CDC.
The CDC changed its surveillance for this type of infection in the vaccinated population on May 1, now only listing cases of severe illness and deaths. A decision criticized by some scientists who deplore the loss of essential data.
Almost 164 million people, or 50% of the US population, have received at least one dose of the vaccine, while 39% are fully vaccinated.