The delta variant doubles the risk of hospitalization: the results of a British study – LCI

More contagious and more severe. These are the conclusions of a British study on the delta variant, published Friday in the journal The Lancet Infectious Diseases. People infected with the latter are twice as likely to be hospitalized for Covid-19 than those infected with the alpha variant.

Scientists already knew that the delta variant, first identified in India, is 40-60% more transmissible than the Alpha variant, which emerged in the UK in late 2020, but little information was yet available on its severity. Preliminary data, in Scotland and Singapore, also suggested an increased risk of hospitalization and severe forms of Covid.

The authors of the study (available online in English) analyzed data from more than 43,000 cases of Covid in England, between March 29 and May 23, when the delta variant began to spread. In the last week of the study, the delta variant accounted for 45% of Covid-19 cases. Three-quarters of the cases referenced by the study (74%) were not vaccinated, a quarter (24%) had received only one dose, fully vaccinated people representing only 1.8% of contaminations .

Given the low proportion of people vaccinated in the study population, “the results of this study tell us above all about the risk of admission to hospital for those who are not vaccinated or partially vaccinated”, underlines to AFP Anne Presanis, statistician at the University of Cambridge.

“While this variant now accounts for over 98% of Covid-19 cases in the UK, it is vital that those who have not received two doses do so as quickly as possible”, recalls Gavin Dabrera, co-author of the study and epidemiologist at Public Health England.

The patients with the delta variant in the UK study were younger, with a median age of 29 years, compared to 31 years for the alpha variant. Several studies have nevertheless shown that the vaccines retain a very high efficacy against the severe forms of Covid linked to the Delta variant, on the condition of having a complete vaccination. Their effect is limited after a single dose.