The Delta variant of the coronavirus is linked to an 85% higher risk of hospitalization, according to a new study from part of the UK.
The findings from Scotland were published in the peer-reviewed medical journal The Lancet on Monday.
Around the same time UK Prime Minister Boris Johnson delayed easing final lockdown restrictions for another four weeks, citing concerns about the fast-spreading variant.
This variant, also known to scientists as B.1.617.2, was first identified in India. It is 60% more transmissible than the variant Alpha (B.1.1.7, first seen in the UK), which had been dominant in the UK but was fast supplanted by the Delta variant.
Delta can now be found in 74 countries, and US officials have warned that it could become dominant in the US.
In the UK, the latest data showed that Delta was to blame for more than 90% of new cases.
Last week, Dr. Antony Fauci, the White House chief medical advisor, warned that the Delta variant, then behind 6% of US cases, could become dominant in the US if people don't get fully vaccinated.
Although the new variant appeared more dangerous, vaccines still help.
Another dataset released by Public Health England the same day showed that vaccines are still effective, albeit to a lesser extent than with earlier variants.
To calculate the increased hospitalization risk, researchers from the University of Edinburgh and Public Health Scotland looked at records from EAVE-II, a surveillance database that tracks COVID-19 cases in Scotland.
The researchers looked at 19,543 confirmed infections, a little fewer than half of which were the Delta variant.
After adjusting for factors such as sex, deprivation, age, and comorbidities, the scientists found that people with the Delta variant were 85% more likely to be hospitalized.
According to the study, the Pfizer and AstraZeneca vaccines provided 79% and 60% protection each, down from 93% and 73% respectively with the previously-widespread Alpha variant.
The authors warned that their data on vaccines was preliminary, and other tests may find different figures.
