20 September 2021

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Covid-19, rare but possible infections among the vaccinated

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In a study published in Lancet Infectious Diseases, researchers from Yale School of Medicine looked at Covid-19 "breakthrough" infections in fully vaccinated people.

"In the United States, the Covid-19 pandemic started 18 months ago. Vaccinations began in December 2020, which significantly reduced the infection rate, but infections, albeit rare, were still observed in fully vaccinated individuals," he explains. Prerak Juthani, first name of the studio.

The researchers looked at data from 969 patients who tested positive for Sars-CoV-2, hospitalized between March and July 2021, and included them in the Yale New Haven Health database. Of the 969 patients, 54 were fully vaccinated at the time of admission or symptom onset. Of these 54 individuals, 14 had a severe illness, and four required admission to the intensive care unit. Analysis of the data showed that most of the most severe breakthrough infections occurred in elderly people with a mean age of 80.5 years and who had other risk factors, such as obesity or diabetes.

"When we started analyzing data from the 14 fully vaccinated patients who had a severe illness, we noticed that these people tended to be older and more comorbid. We are working to understand better what additional factors may be involved in the development of serious infections. From Covid-19 after vaccination, so that we can identify strategies to prevent these cases in the future in the population, "says Juthani.

The researchers point out that while this study focused on breakthrough infections, it is important to note that over 94% of hospitalized patients had not been fully vaccinated at the time of admission. Their data once again confirms that the vaccines are extremely effective.

Source: https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(21)00558-2/fulltext