People infected with the more contagious coronavirus variant first identified in the UK did not experience worse symptoms and did not have a higher risk of death, according to a new study published Monday.
Scientists are struggling to determine the nature of the British variant, which has become the dominant strain in Europe and since last week in the United States. Most important among the questions: Is the variant more deadly?
The study, published in The Lancet Infectious Diseases, looked at data from last autumn in the UK, shortly after the variant was first detected. It spread rapidly and eventually became the dominant tribe that spread throughout the country.
The new findings contribute to the understanding of scientists’ ongoing development of the British variant, known as B.1.1.7, at an important time in the pandemic, as it and other variants spread widely in other countries.
Researchers looked at Covid-19 patients admitted from University College London Hospital and North Middlesex University Hospital from 9 November to 20 December. 42 percent were infected with another strain.
The researchers then compared the severity of symptoms between the two groups and found that patients infected with the B.1.1.7 variant did not have the increased risk of becoming seriously ill or dying. The study came at a time when the British variant was only gaining a foothold in London – and when the UK vaccination program was underway.
“We were able to do this real-time analysis because we were in the eye of the storm,” said lead author of the study, Dan Frampton, a bioinformatics scientist at University College London.
The study found that samples from patients with the B.1.1.7 variant had larger amounts of viruses or higher “viral loads”, but it is not yet clear why.
“One idea why this variant is more transmissible may be that patients are making more viruses,” Frampton said.
He said that although the researchers did not find a link between the British variant and the severity of diseases, the patients hospitalized with variant B.1.1.7 at the time were probably under the age of 60 and from ethnic minority backgrounds. .
Patients with B.1.1.7 also received more oxygen. Frampton said this is not necessarily an indication of worse illness and that more research is needed.
“There are clearly a lot of interesting things to look at,” he said. “We are now in a much better position to start studying what small results look like and to look in more detail to portray the picture more.”
There was no consensus on the virulence and mortality of the strain and whether it caused serious illness and death.
An article published in the journal Nature last month found that the B.1.1.7 variant could be associated with a 61 percent higher risk of death than existing variants. Earlier in March, research published in The BMJ found that people older than 30 had a 64 per cent higher risk of death due to the British variant. In that study, however, the scientists said that the “absolute risk of death in this largely unvaccinated population remains low.”
Dr. Eric Topol, director of the Scripps Research Translational Institute in California, who was not involved in the new study, said the conflicting results show how much remains to be learned about the B.1.1.7 variant.
“The new findings nullify the other articles, but make you think,” he said. “Maybe the truth is somewhere in the middle. This study says that there is no higher mortality rate, but that they did need more oxygen, so there is something going on regarding this variant.”
Although there are some indications that the B.1.1.7 variant affects young people more than previous strains, there is not enough data to know for sure, Topol said. And it can be difficult to distinguish other factors that can calculate the trend.
“This is one of the troublesome things of this varying epidemiology,” he said. “There are a lot of moving parts – age, resources, existing circumstances – and you can’t always adapt to all of those things.”
A variant that is more contagious could probably mean that there will be more cases among children and young people, of which there were not the most vulnerable to Covid-19 before.
“It does not mean that the virus finds them preferable. It just means that we would expect more from younger people, because it generally causes higher virus load and more spread,” Topol said.
Another area that needs more research is the effect of the British variant on immunity. A separate study published in The Lancet Public Health on Monday examined self-reported data from nearly 37,000 people in the UK and found that the rate of re-infection was low. The findings were based on surveillance data submitted by the app over 13 weeks from September to December, when the number of cases of the British variant exploded in London and south-east England.
The researchers found that only 249 out of 36,509 people out of those who reported positive tests or 0.7 percent before Oct. 1 tested positive again more than 90 days later. In other words, people infected with an existing variant do not have a greater risk of being re-infected with the B.1.1.7 variant.
“This suggests that B.1.1.7 does not evade the immunity that humans develop against infection by previous diseases,” said lead author of the article, Mark Graham, a research fellow at King’s College London.
Graham and his colleagues are watching for re-infections, especially as larger sections of the population in the UK and elsewhere are being fully vaccinated. Studies have shown that current vaccines offer strong protection against the British variant, and Graham said that long-term studies of immunity would provide more clarity on not only the B.1.1.7 strain, but also other possible concerns that may arise.
“The introduction of vaccines is going remarkably well in the UK, and it makes a big difference, but the one unknown factor that could derail this progress is new variants,” he said. “Understanding how it can affect us will be very important.”