Lancet study: Delta variable doubles hospitalization risk
People infected with the delta variant of SARS-CoV2 are at twice the risk of hospitalization than those with the alpha variant. These are the results of a British study published today in The Lancet. “Our analysis shows that if vaccines were not available, an epidemic due to the delta variant would affect health systems much more than if it was caused by alpha,” said study co-author Anne Brisanis.
The researchers analyzed data from more than 43,000 Covid cases recorded in England between March 29 and May 23, when Delta began spreading through the channel. The proportion of cases associated with the alpha variant was 80% in the mean of the studied period (99.8% first week, 34.8% last), 20% of the delta variant. Three quarters of patients (74%) were not vaccinated and a quarter (24%) received only one dose. Those who received both administrations represented only 1.8% of those infected.
2.3% of the delta-positive cases were hospitalized in the two weeks following the positive test, versus 2.2% of the alpha variant cases. But by paraphrasing the data to assess known factors that differ from the risk of severe forms (age, ethnic group, and vaccination status), the researchers calculated that the risk of hospitalization multiplied by 2.26 with a delta variable compared to alpha. Delta patients were younger, with a mean age of 29 versus 31 with alpha.