October 5, 2021
EDMONTON — COVID-19 variants of concern (VOCs), particularly the Delta variant, cause more severe illness than the native strain of the virus, increasing the risk hospitalization, admission to the intensive care unit (ICU) and death, according to a large Canadian study released Tuesday.
The study found that people infected with VOCs were significantly younger and less likely to have comorbidities than those with non-VOC infections, and, even after adjusting for age, sex, comorbidities and other factors, the increased risk of adverse outcomes persisted.
Using case data from Ontario, the country’s most populated province, the study included 212,326 cases of COVID-19 reported between Feb. 7 and Jun. 26, 2021. Variants of concern included those with the N501Y mutation such as Alpha, Beta and Gamma as well as Delta, which have replaced the original SARS-CoV-2 strain.