The United States reported on Tuesday its first confirmed case of Covid-19 from a variant of the coronavirus that is believed to have emerged from the UK, a new cause for concern, as new research has found it to be more contagious than other strains .
Colorado Governor Jared Polis announced that the state identified the case in a man in his 20s with no recent travel history. It is the first known infection of the newly identified strain in the United States, and most experts say more are likely to arise.
“There is a lot we don’t know about this new variant of Covid-19, but UK scientists are warning the world that it is significantly more contagious,” Polis said at a news conference on Tuesday.
It is not uncommon for viruses to mutate and, in fact, several other variants of the coronavirus have already been reported. But so far, most mutations have had no significant impact on how the virus spreads or how infected people get sick.
The new variant, dubbed VUI-202012/01, has a handful of mutations in its genetic code. Notably, “these changes have been predicted to have the potential to make the virus more quickly transmissible,” according to the Centers for Disease Control and Prevention.
Many hospitals in the USA are already in crisis. The concern is that a more contagious variant of the virus could increase the number of new cases and put even more pressure on the health system.
“If you have twice as many cases, even if the number of sick people is the same as today, that would definitely be bad,” said Dr. Diane Griffin, professor of molecular microbiology and immunology at the Johns Hopkins Bloomberg School of Public Health. “Anything that increases the number of cases would be bad.”
The new variant has been identified in more than a dozen other countries, including France, Denmark, Japan, South Korea and Canada. But because there is no widespread effort in the U.S. to conduct regular genome sequencing of samples from across the country, it is likely that the variant is already spreading in the U.S., Griffin said.
“I’m sure it’s already spreading around here and we just don’t know it yet,” said Griffin, who called for better monitoring of the virus’s evolution as part of a committee of the National Academy of Sciences. “This is the reason why we really try to pressure the United States to have a better surveillance system, so that we are constantly monitoring what the virus is doing here and so that we can see when a new version arrives.”
Scientists in the UK are conducting this type of forensic work now.
A new report by the country’s Department of Health and Social Care found that the newly identified variant does not appear to be more deadly and does not cause more serious illness.
While the findings provide some relief, experts say that as the new variant is more contagious, there is still an acute risk that health systems will be overwhelmed in the weeks and months ahead.
“One of the mutations identified is known to increase the virus’s ability to bind to its receptor,” said Griffin. “So it makes some sense that it is more communicable.”
The new report, published by Public Health England, found that the variant cases had no increased risk of reinfection and did not have a higher fatality rate. The study compared 3,538 cases of Covid-19, of which almost 2,700 were identified through genome sequencing as involving the new variant of the coronavirus.
The severity of the disease and death are not the only causes of concern for countries that are battling serious outbreaks of infection, such as the United Kingdom. If the virus can now spread faster through communities, for example, more hospitalizations and deaths will occur naturally.
More research is needed, but the increased transmissibility of the new variant may mean that its so-called reproduction number has changed. This number, called R-nada, is an estimate of the average number of people that a patient with Covid-19 can infect and is used to represent how contagious a disease is.
Apparently minimal changes in the number of reproductions – R-zero increasing from 1.1 to 1.3, for example – can represent large increases in potential infections due to the way the pathogens spread.
“An increase in something that grows exponentially (ie, transmission) can have much more effect than the same proportional increase in something that only scales a result (ie, severity),” said Adam Kucharski, mathematician and epidemiologist at the London School of Hygiene & Tropical Remedy, wrote on Twitter.
It is estimated that the new variant may be 50% to 70% more transmissible, but more research is needed to understand why.
Another major unknown is the impact that the new variant will have on immunity, if any. There is still no evidence to suggest that the same antibodies that recognize the virus will also not work against the new variant, but it is the type of development that keeps epidemiologists on edge.
“One of the things that worries us is whether it changes the vaccine’s effectiveness?” Griffin said. “We have no evidence that this mutation does this, but when viruses mutate, we always worry about what it means for immunity or to become resistant to drugs.”
A separate variant of the coronavirus reported in South Africa is also considered to be more contagious, but research is still ongoing to better understand its characteristics.
“Laboratory studies take time and we expect more information in the coming days and weeks,” said Maria Van Kerkhove, Covid-19 technical leader for the World Health Organization, on Monday at a news conference on the new variants identified .
As scientists rush to discover more details about the new variants, experts say it is more important than ever to follow public health guidelines.
“All the things we’ve been saying – wear a mask, practice social detachment and avoid mixing families – these mitigation strategies will continue to work,” said Griffin. “The problem now is that not everyone is following them.”