According to a big new British study, people infected with the highly contagious Delta variety are twice as likely to be hospitalised as those infected with the Alpha type.
The study, which was published on Friday in The Lancet Infectious Diseases journal, looked at almost 40,000 coronavirus infections in England. It adds to the growing body of research that suggests Delta causes more severe illness than other variations.
Fewer than 2% of the illnesses occurred among fully vaccinated patients, and the researchers stated there was insufficient evidence to draw solid conclusions about hospitalisation risks in that group.
The main takeaway is that if you have a population that is unvaccinated or only partially vaccinated, an outbreak of Delta can put a greater strain on hospitals and health-care systems than an outbreak of Alpha, said Anne Presanis, a senior statistician at the University of Cambridge and one of the study’s lead authors.
The Delta version, discovered in India, is nearly twice as infectious as the original virus and up to 60% more transmissible than the Alpha form, which was discovered in the United Kingdom.
Researchers studied the health data of patients who tested positive for the virus in England between March 29 and May 23, when Delta was spreading across the country, for the current study. 74% of people were unvaccinated, 24.2 percent were partially vaccinated, and only 1.8 percent were fully vaccinated.
The researchers discovered that the risk of hospitalisation was low in both groups. Within two weeks of testing positive for the virus, just 2.2 percent of people with Alpha and 2.3 percent of those with Delta were admitted to the hospital.
“We already know that vaccination provides excellent protection against Delta, and given that this variant accounts for over 98 percent of Covid-19 cases in the United Kingdom, it is critical that those who have not yet received two doses of vaccine must do so as soon as possible,” said Dr. Gavin Dabrera, lead author of the paper and an epidemiologist at Public Health England.