The data are in: People infected with the coronavirus variant first discovered in the UK have a higher risk of dying from COVID-19 than those who contract other versions of the virus.
New research published on Monday in the journal Nature found that among cases involving the variant, known as B.1.1.7, patients had a 55% greater chance of death within four weeks after their positive test.
The study authors examined about 2.2 million people tested positive in England between September and mid-February, then compared the number of deaths between those with B.1.1.7 and those who were infected with other strains.
After controlling for variables such as the patient’s age, sex, ethnicity and lifestyle, the researchers found that with the original virus, about six in every 1,000 people in their 60s who tested positive could die. But that number rises to about nine in 1,000 with B.1.1.7.
“Despite substantial advances in treatment with COVID-19, we have seen more deaths in 2021 than in the first eight months of the pandemic in 2020. Our work helps to explain why,” Nick Davies, the study’s lead author and an epidemiologist at London School of Hygiene and Tropical Medicine, said in a press release.
In January and February, 42,000 people died in England from COVID-19.
Increasing evidence shows that variant B.1.1.7 is more deadly
B.1.1.7 was discovered outside London in September, but initial evidence suggested that the strain was no longer lethal. Then, in January, UK Prime Minister Boris Johnson announced that the variant was probably associated with higher mortality.
Research published last week in the BMJ magazine confirmed this. He found that B.1.1.7 is more deadly than other strains – and even more deadly than the results of the Nature study suggest.
BMJ researchers examined about 55,000 pairs of people in the UK. Within each pair, one person tested positive for B.1.1.7, while the other tested positive for a different strain of coronavirus (including variants from South Africa and Brazil). The members of each pair had similar ages, ethnicities and geographic locations and obtained positive test results between October and February.
The study found that variant B.1.1.7 was 64% more deadly than other strains in the four weeks following a positive test.
Prime Minister of the United Kingdom, Boris Johnson.
Getty
Johnson’s January announcement was based on research collected by the New and Emerging Respiratory Virus Threat Advisory Group, which found that, on average, people infected with B.1.1.7 in the UK had a 30% higher mortality rate than those with the original virus.
A follow-up analysis by Public Health England analyzed data collected between late November and early January, and found that B.1.1.7 was 65% more deadly than other strains. Meanwhile, researchers at the University of Exeter analyzed samples collected between October and the end of January and found that people infected with the variant were almost twice as likely to die.
Higher mortality may be related to higher viral loads
A COVID-19 patient is taken to an ambulance in London.
Getty
The increased lethality of the strain can be attributed to the fact that people infected with B.1.1.7 have higher viral loads on average, which means that they produce more viral particles when they are infected. Higher viral loads, several studies show, are associated with an increased risk of death and more serious illnesses.
“That was the first thing that certainly came to mind,” William Schaffner, an infectious disease specialist at Vanderbilt University, told Insider. “It would make a lot of sense.”
It is also possible that the increase in the transmissibility of the strain simply gives the virus a better chance of infecting more people with a higher risk of serious diseases. A more communicable strain means that people are more likely to be infected if exposed; B.1.1.7 is between 50% and 70% more contagious than the original version of the virus.
This increased transmissibility may be due to several mutations in the virus spike protein’s genetic code, which it uses to invade cells. These adjustments can make it easier for variant B.1.1.7 to spread.
“It may simply be a matter of a more contagious virus reaching more vulnerable people, older people or those with underlying health problems, such as
diabetes
or lung disease, “said Schaffner.
Yet another possibility is that the increased transmissibility of the variant indirectly contributed to a higher mortality rate due to the stress it placed on the UK health system. The number of daily COVID-19 cases there skyrocketed in the four months after the discovery of B.1.1.7, jumping from 3,899 new cases on September 20 to more than 68,000 cases on January 8.
The increase in cases has undermined UK hospital and health care resources, which may have affected patient outcomes.
“If their cases get out of hand, their deaths will get out of hand as their health care system is under pressure,” said Mike Ryan, executive director of the World Health Organization’s health emergency program, in January.
Existing vaccines work against B.1.1.7
A woman receives a COVID-19 vaccine in Wales.
Getty / Matthew Horwood
B.1.1.7 was found in 94 countries, including the USA.
But in recent studies, both Pfizer and Moderna have found that their shots have resisted the variant well. Other vaccines, including those of Johnsen & Johnsen and AstraZeneca, also protect people from B.1.1.7.
But these injections appear less effective in general against the variant first discovered in South Africa, B.1.351, and the strain found in Brazil, called P.1.
This is probably because these two variants share a mutation that can prevent antibodies generated in response to the original virus from recognizing them. This genetic adjustment is mainly lacking in B.1.1.7, although researchers in the United Kingdom have found 11 cases of B.1.1.7 with this mutation in a set of more than 200,000 samples.
Studies have not found B.1.351 or P.1 to be more lethal than the original virus.