Delta Variant More Than Doubles Risk Of Covid Hospitalization, U.K. Study Finds

According to a study published in The Lancet Infectious Diseases journal Friday, people infected by the delta variant of Covid-19 are twice as likely to be admitted to hospital for treatment than those infected with alpha variant. This confirms previous research that suggests the hyper-infectious variant could cause more severe diseases.

TOPSHOT - A COVID-19 coronavirus victim was treated by medical staff at Wuhan's central Hubei province hospital on March 19, 2020. China reported no new cases of coronavirus in its domestic population on March 19, but it did record an increase in foreign infections. (Photo: STR / AFP). / China OUT. (Photo taken by STR/AFP via Getty Images). AFP via Getty Images

The Key Facts

Public Health England (PHE), and Cambridge University analyzed healthcare data from 43 338 coronavirus positive cases in England between March 29th and May 23. They determined that the cases were either caused by the alpha or the delta variants through whole-genome sequencing. This is the best way to identify a virus variant. Alpha, a mutation that originated from the U.K., spreads faster than other variants, made up the majority of the analyzed cases (80%). However, it had been overtaken by delta by the end. Data indicate that delta is between 40%-60% more transmissible to coronavirus than U.K. variants. Seventy-four of the 34,656 cases of alpha were admitted to hospital within 14 days after testing positive. Only 196 (2.3%) of the 8,682 cases of delta were admitted to hospital. The risk of hospital admission increased by 2.26 times with the delta variant after adjusting for age, race, and vaccination status, which are all known factors that can affect the susceptibility to severe illness caused by Covid-19. The peer-reviewed study found that the risk of being admitted to hospital increased 2.26 times with the delta variant. This was despite the fact that the alpha and beta variants are more common in people who have received both vaccine doses.

Important Quote

Our analysis shows that any delta epidemics without vaccination will be more costly than an alpha outbreak. Dr. Anne Presanis is a Senior Statistician at the Medical Reserve Corps, and the lead author of this study. It is essential to get fully vaccinated in order to reduce the risk of developing symptomatic delta infection. Also, it will help to lower the risk of serious illness and hospitalization for delta patients.

Important Background

This study confirms previous research that suggests the delta variant is more likely than alpha to cause hospitalizations. In June, a Scottish study found that delta, which was first identified in India in April, had twice the likelihood of hospitalization than alpha. Similar studies from Canada and Singapore suggest that delta can lead to severe illness. The research from Singapore found that coronavirus-infected patients infected with delta were more likely than alpha to need oxygen. These three studies were cited by the Centers for Disease Control and Prevention in an internal report. News organizations made public their concerns about the delta variant in July. On its website, the agency admits that data suggests that the delta variant could cause severe illness in people who have not been vaccinated.


The virus' delta variant has caused a huge increase in hospitalizations in the United States. Since January, more than 100,000 people have been hospitalized. The virus is primarily affecting unvaccinated Americans. It is currently overwhelming multiple states' healthcare systems with inoculation rates lower than the national average. According to The New York Times, Covid-19 is causing approximately 1,200 deaths per day.