According to a new study whose results were released on Friday, those who get infected with the Delta variant of the coronavirus are twice as likely to ultimately fall severely ill and require hospitalization compared to those who get infected by the Alpha variant of the virus that was first detected in England last year.
The study was conducted on more than 43,000 Covid-19 patients in England, most of whom were unvaccinated. The study then dissected the data from these patients on the basis of those infected with the Delta variant, which was first discovered in India earlier this year, and those with the Alpha variant with the aim of ascertaining the risks of hospitalization of the two groups of infected people.
“Our analysis highlights that in the absence of vaccination, any Delta outbreaks will impose a greater burden on healthcare than an Alpha epidemic,” Anne Presanis, one of the study’s lead authors and a University of Cambridge statistician, said.
The study was conducted on the infection cases that were detected March and May – during the initial stages of mass vaccination campaign in the country and hence the study was unable to assess the extra risk of hospital admission for people who had not been vaccinated yet or were partially vaccinated.
In fact the study comprised of only 1.8 per cent of the cases examined for comparison of the two variants were fully vaccinated. About three quarters of the patients of the study completely unvaccinated, and 24 per cent had been administered only one dose of a two-dose Covid-19 vaccine.
“The results from this study therefore primarily tell us about the risk of hospital admission for those who are unvaccinated or partially vaccinated,” said co-lead author Anne Presanis, a senior statistician at the University of Cambridge’s MRC Biostatistics Unit.
The elements in individual cases of infection that were examined included vaccination status, emergency care, hospital admission and other patient information, which were then used for comparison.
The researchers conducted whole genome sequencing for all of the virus samples which is the surest method to confirm the type of variant that had caused the infection.
The study showed that a little below 80 per cent of the infections was caused by the Alpha variant of the coronavirus while the rest were caused by the Delta variant. The study found that about one in 50 patients had to be admitted to hospital within 14 days of people being diagnosed with Covid-19.
While comparing the impact of the two variants of the coronavirus, the researchers accounted for the factors that are established to increase chances of severe illness and hospitalization, including age, ethnicity, and vaccination status, and found that people infected by the Delta variant ran a more than double risk of hospitalization compared to those infected with the Alpha variant.
The study, published in the Lancet Infectious Diseases journal, was the largest so far to analyse Covid-19 cases confirmed by virus genome sequencing.
(Adapted from AlJazeera.com)