Reports from Britain and South Africa of new strains of coronavirus appearing to spread more easily raise alarm, but virus experts say it is unclear whether this is the case or whether they are concerned about vaccines or causing more serious illnesses. .
Viruses naturally evolve as they move through populations, some more than others. It’s one of the reasons we need a new flu vaccine every year.
New variants, or strains, of the virus that causes COVID-19 have been observed almost since it was first discovered in China nearly a year ago.
On Saturday, Prime Minister Boris Johnson announced new restrictions due to the new species. Several countries of the European Union and Canada have banned or restricted some flights from the UK to try and limit any potential spread.
This is what is known about the situation.
What about the recent species found in England?
Health experts in the UK and US said the species appears to be easier to infect than others, but there is no evidence yet that it is more deadly.
Patrick Vallance, the UK government’s chief scientific adviser, said the species is “fast moving and becoming the dominant variety,” which caused more than 60% of infections in London in December.
The strain is also of concern because it has many mutations – nearly two dozen – and some are in the spikey protein that the virus uses to bind and infect cells. That increase is the goal of current vaccines.
“I am certainly concerned about this,” but it is too early to know how important it will ultimately prove to be, said Dr. Ravi Gupta, who studies viruses at the University of Cambridge in England. He, along with other researchers, published a report on a website that scientists use to quickly share developments, but the paper has not been formally reviewed or published in a journal.
How are these new varieties produced?
Viruses often acquire small one or two letter changes in their genetic alphabet simply through normal evolution. A slightly modified strain may become the most common strain in a country or region simply because it is the strain that first emerged there, or because “super spreader” events helped hold.
A bigger concern is when a virus mutates by altering the proteins on its surface to help it escape drugs or the immune system.
“Emerging evidence” suggests this may be starting to happen with the new coronavirus, Trevor Bedford, a biologist and genetic expert at the Fred Hutchinson Cancer Research Center in Seattle, wrote on Twitter. “We have now seen the emergence and spread of several variants” suggesting this, and some showing resistance to antibody treatments, he noted.
What other species have emerged?
In April, researchers in Sweden found a virus with two genetic changes that made it about twice as contagious, Gupta said. About 6,000 cases have been reported worldwide, mainly in Denmark and England, he said.
Now several variants of that kind have appeared. Some were reported in people who obtained them from mink farms in Denmark. A new South African species has the two changes above, plus a few others.
The British has two and more changes, including eight in the spike protein, Gupta said. It is called the “research variant” because its meaning is not yet known.
The species was identified in southeast England in September and has been circulating in the area ever since, a World Health Organization official told the BBC on Sunday.
Will people who have had COVID-19 of an old kind be able to get the new one? Will it allow vaccines?
Probably not, former US Food and Drug Commissioner Scott Gottlieb said on CBS’s “Face the Nation” on Sunday.
“Unlikely,” Gupta agreed.
President-elect Joe Biden’s surgeon general candidate Vivek Murthy said on NBC’s “Meet the Press” Sunday that “there is no reason to believe that the vaccines that have been developed will also be ineffective against this virus.”
The vaccines elicit broad responses from the immune system beyond those of the spike protein, several experts noted.
The likelihood that the new strains will be resistant to existing vaccines is small, but not “non-existent,” said Dr. Moncef Slaoui, the US government’s chief scientific adviser on vaccine distribution, Sunday. CNN’s “State of the Union” show.
“So far I don’t think there is one variant that is resistant,” he said. “I think it is highly unlikely that this particular variant has escaped vaccine immunity in the UK.”
Bedford agreed.
“I’m not worried” because it likely takes many changes in the genetic code to undermine a vaccine, not just one or two mutations, Bedford wrote on Twitter. But vaccines may need to be adjusted over time as changes accumulate, and changes need to be monitored more closely, he wrote.
Murthy said the new species does not change public health advice to wear masks, wash hands, and maintain social distance.