According to a study released Friday, people infected with the Delta version of COVID-19 had roughly twice the chance of hospitalisation as those infected with other varieties of the virus.
In addition, the risk for visiting the hospital emergency room due to symptoms of COVID-19 or being admitted to the hospital within 14 days of infection is 1.5 times higher with the Delta variant than the earlier version of the virus, researchers reported in the study published in Lancet Infectious Diseases.
“This study confirms previous findings that people infected with Delta are significantly more likely to require hospitalization than those with Alpha, although most cases included in the analysis were unvaccinated,” study co-author Gavin Dabrera said in a press release.
“We already know that vaccination offers excellent protection against Delta and it is vital that those who have not received two doses of vaccine do so as soon as possible,” said Dabrera, a consultant epidemiologist at the National Infection Service for Public Health England in London, where the research was conducted.
The Delta variant first was identified in India in the later winter, while the Alpha variant, or “U.K. variant,” first was reported in England in September, according to Dabrera and his colleagues.
Their findings are based on an analysis of healthcare data from more than 43,000 positive COVID-19 cases in England between March 29 and May 23, including information on vaccination status, emergency care attendance, hospital admission and other demographic characteristics.
In all cases included in the study, samples of the virus taken from patients underwent whole genome sequencing to confirm which variant had caused the infection, the researchers said.
According to the researchers, approximately 35,000 occurrences of the alpha version and roughly 8,700 cases of the Delta variant occurred throughout the study period.
Although Delta instances accounted for 20% of new COVID-19 cases in the study period, the strain rose to account for almost two-thirds of new COVID-19 cases in the week beginning May 17, indicating that it had surpassed alpha to become the prevalent variety in England, according to the researchers.
However, fewer than 2% of the cases involving either variation had received both doses of a COVID-19 vaccination, while 74% were unprotected and 24% were partially vaccinated, according to the researchers.
“Our analysis highlights that in the absence of vaccination, any Delta outbreaks will impose a greater burden on healthcare than an Alpha epidemic,” study co-author Anne Presanis said in a press release.
“Getting fully vaccinated is crucial for reducing an individual’s risk of symptomatic infection with Delta in the first place, and, importantly, of reducing a Delta patient’s risk of severe illness and hospital admission,” said Presanis, senior statistician at the University of Cambridge in England.
The Pfizer-BioNTech shot was given final approval by the US Food and Drug Administration last week for use in adults aged 16 and up. Under the FDA’s emergency use permission, people aged 12 to 15 are eligible to get the vaccination.
According to CDC data, about 165,000 new COVID-19 cases were recorded across the United States on Thursday, with at least 80% of them being the more contagious Delta type.