The Delta variant, almost non-existent in January, now represents 99% of contaminations in France and 99.3% of sequences deposited in the Gisaid database at the international level for the period from August 29 to September 21, 2021, according to an analysis of Public Health France. Several studies have already attested to the greater contagiousness and the greater virulence of the Delta variant (see diagram below). It is also more likely to escape the vaccine: the effectiveness rate of Moderna and Pfizer vaccines thus goes down to 66% with this variant, against more than 90% with the original virus.
A 133% increased risk of death
A new large study, carried out in Canada, confirms the extreme virulence of this variant. Carried out on 212,326 people between February and June 2021, the latter examined the risks of hospitalization, admission to the emergency room and of death linked to the various variants then in circulation (Alpha, Beta, Gamma and Delta) compared to the original virus. Result: the risks of hospitalization, admission to the emergency room and death are increased by 108%, 235% and 133% respectively with the Delta variant. In other words, where one in 100 people died from the original SARS-CoV-2, 2.33 people die when infected with the Delta variant.
The emergence of new variants has slowed progress against the pandemic
Virulence is also higher with the Alpha, Beta and Gamma variants, but to a lesser extent (52% for the risk of hospitalization, 89% for the risk of emergency room admission and 51% for the risk of death). ” Even adjusted for factors of age, sex and co-morbidities, the risk persists “, Insist the researchers. ” The emergence of new variants of SARS-CoV-2 has slowed progress against the pandemic in three distinct ways “, Argues David Fisman, co-author of the article published in the journal CMAJ (Canadian Medical Association Journal), namely by increasing the transmissibility and …
> Read more on Futura
Read also on Futura