Reports in the UK and South Africa of new strains of coronavirus that appear to be spreading more are alarming, but virus experts say it is unclear whether this is the case or whether it raises concerns about vaccines or causes more serious disease. .
Viruses evolve naturally as they move through populations, some more so than others. It is one of the reasons why we need a new flu vaccine every year.
New variants or strains of the virus that cause COVID-19 have been observed almost since it was first detected in China almost a year ago.
On Saturday, Prime Minister Boris Johnson announced new restrictions due to the new strain. Several countries in the European Union and Canada have banned or restricted some flights in the UK in an attempt to limit any spread.
Here is what is known about the situation.
How about the recent strain found in England?
Health experts in the UK and the US have said the strain appears to infect more easily than others, but there is still no evidence that it is more deadly.
Patrick Vallance, the British government’s chief scientific adviser, said the strain was “moving fast and becoming the dominant option”, causing more than 60% of infections in London in December.
The strain is also worrisome because it has many mutations – nearly two dozen – and some are in the spikey protein that the virus uses to bind and infect cells. This increase is the purpose of current vaccines.
“I’m worried about that, sure,” but it’s too early to know how important it will eventually prove to be, said Dr. Ravi Gupta, who studies viruses at Cambridge University in England. He and other researchers have published a report on the subject on a website that scientists use to quickly share developments, but the article has not been officially reviewed or published in a journal.
How are these new strains produced?
Viruses often acquire small changes of a letter or two in their genetic alphabet simply by normal evolution. A slightly modified strain may become the most common in a country or region, simply because it is the strain that first caught on there or because the “super-spreading” events helped to prevail.
A major concern is when a virus moves by changing the proteins on its surface to help it get rid of drugs or the immune system.
“Emerging evidence” suggests that this could start to happen with the new coronavirus, wrote Trevor Bedford, a biologist and genetic expert at the Fred Hutchinson Cancer Research Center in Seattle, on Twitter. “We have now seen the emergence and spread of several variants” that suggest this, and some are resistant to antibody treatments, he noted.
What other strains have appeared?
In April, researchers in Sweden discovered a virus with two genetic modifications that appeared to make it twice as infectious, Gupta said. He said about 6,000 cases had been reported worldwide, mainly in Denmark and England.
Several variants of that strain have now appeared. Some have been reported to people who obtained them from mink farms in Denmark. A new South African strain has the two changes seen above, plus a few others.
The UK has two or more changes, including eight in the protein spike, Gupta said. It is called the “investigation variant” because its significance is not yet known.
The strain was identified in the south-east of England in September and has been circulating in the area since then, a World Health Organization official said on Sunday.
Will people who had covid-19 from an old strain be able to receive the new one? Will it allow vaccines?
Probably not, former US Food and Drug Commissioner Scott Gottlieb told CBS’s “Face the Nation” on Sunday.
“Less likely,” Gupta agreed.
Vivek Murthy, a candidate for President-elect Joe Biden’s general surgeon, told NBC’s “Meet the Press” on Sunday that “there is no reason to believe that the vaccines that have been developed will not be effective against the virus.”
Vaccines elicit extensive responses by the immune system beyond those of the spike protein, several experts noted.
The chance that the new strains will be resistant to existing vaccines is small, but not “non-existent,” Dr. Moncef Slaoui, chief scientific adviser to the U.S. government’s vaccine distribution effort, said Sunday. CNN’s “State of the Union” show.
“So far, I don’t think there has been a single option that is resilient,” he said. “I think it is very unlikely that this special variant in the UK has escaped the vaccine’s immunity.”
Bedford agreed.
“I’m not worried, because it would probably take many changes to 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 build up and changes need to be monitored more closely, he wrote.
Murthy said the new strain does not change public health advice to wear masks, wash hands and maintain social distance.