LONDON — British government scientists are increasingly finding the coronavirus variant first detected in Britain to be deadlier than the original virus, a trend that highlights the risks of this new phase of the pandemic.
The scientists said last month that there was a “realistic possibility” that the variant was more lethal. Now, they say in a new document that it is “likely” that the variant is connected to an increased risk of hospitalization and death.
The updated findings are based on roughly twice as many studies as their earlier assessment and include more deaths from cases of COVID-19 caused by the new variant, known as B.1.1.7.
The variant is known to be in 82 countries. American scientists have said that it could be the dominant version of the virus in the United States by March.
Most COVID-19 cases, even those caused by the new variant, are not fatal. And the government scientists were relying on studies that examined a small proportion of overall deaths, making it difficult to pinpoint how much increased risk may be associated with the variant.
But the strongest studies they relied on estimated that the variant could be 30% to 70% more lethal than the original virus.
The variant is thought to be 30% to 50% more transmissible than the original virus, though some scientists now believe it is even more contagious than that. It now accounts for more than 90% of cases in many parts of Britain.
The government scientists cited a study from the London School of Hygiene and Tropical Medicine. In January, that study examined the deaths of 2,583 people, 384 of whom were believed to have had cases of COVID-19 caused by the new variant. The research estimated that people infected with the new variant had a 35% higher risk of dying.
An updated study by the same group relied on 3,382 deaths, 1,722 of which were believed to be from the new variant. That study suggested that the variant could be connected with a 71% higher risk of dying.