People infected with the Delta variant of Coronavirus (Covid-19) are twice as likely to be hospitalised than those infected with the Alpha variant, according to a British study published on Friday.
“Our analysis highlights that in the absence of vaccination, any Delta outbreaks will impose a greater burden on healthcare than an Alpha epidemic,” Dr. Anne Presanis, one of the study’s co-authors, said.
It is already known that the Delta variant, first detected in India, is about 40% to 60% more transmissible than the Alpha strain, which emerged in the United Kingdom in late 2020.
The authors of the study, published in The Lancet Infectious Diseases Journal, analysed data from over 43,000 Covid-19 cases occurring in England between 29 March and 23 May, the period in which the Delta variant began to spread there.
Sequencing showed that the Alpha strain accounted for 80% of all cases during that period, but its share went down from 99.8% in the first week to 34.8% in the last. Delta was responsible for an average of 20% of cases.
Vaccinated persons represented just 1.8% of the infections, while 74% of the infected had not been vaccinated and 24% had received only a single dose.
The study found that 2.3% of patients with the Delta variant and 2.2% of patients with the Alpha variant were admitted to the hospital within two weeks after they tested positive for Covid-19.
However, when factors that raise patients’ risk for hospitalization - such as age, ethnicity and vaccination status - were accounted for, the researchers found that the hospitalisation risk was 2.26 times higher with the Delta variant than with the Alpha variant.
Patients infected with the Delta variant were also younger, with a median age of 29 years, as against 31 years for the Alpha variant.
The Brussels Times
