Two major variants of the virus that causes COVID-19 have emerged in recent weeks, raising questions about their contagiousness and accuracy of testing – but neither is more dangerous than the virus that has circulated for the last year, experts say, and available vaccines should remain effective.
COVID-19 testing labs across the U.S. should be monitoring samples for mutated variants of the virus, the Food and Drug Administration said Friday. There is a chance the mutations will cause some tests to return false-negative results,the agency warned, though it’s unlikely most tests will miss people who are contagious.
“The FDA believes the risk that these mutations will impact overall testing accuracy is low,” according to the statement.
In more than a year of circulation, the virus has mutated many times, but only these most two recent variants – one that appeared first in the United Kingdom and the other in South Africa – seem to make a substantial difference in its function.
Only the U.K. strain, known as B.1.1.7, has been detected in the U.S., currently in eight states, according to the U.S. Centers for Disease Control and Prevention. While it may spread more easily and quickly than other variants, the agency says there is no evidence it makes people sicker or increases risk of death.
A more contagious coronavirus strain? Here’s what we know.
Viral mutations cause concerns because they can make tests, treatments and vaccines ineffective, and change the properties of a disease, making it more or less transmissible and dangerous.
The new variants appear to be pushing out older ones, raising worries about whether the changes will affect the course of disease or efforts to rein it in. So far, though, the new variants do not seem to be a cause for huge concern.
The two authorized vaccines and others under development are expected to continue to be effective against the two variants, which have spread to at least 33 countries, experts say.
Pfizer-BioNTech, the team making one of the authorized vaccines, released findings late Thursday showing that blood from people who have been vaccinated can effectively neutralize the mutated variants.
In another study published this week, led by researchers at the Fred Hutchinson Cancer Research Center in Seattle but also not yet peer reviewed, scientists found the blood of people who recovered from COVID-19 was able to completely vanquish the British variant. That suggests it won’t pose a problem for people who have been vaccinated or already recovered from COVID-19.
The South African variant was less well-controlled, the researchers found, but Jesse Bloom, the senior author, said on Twitter he’s not yet concerned about vaccines losing effectiveness.
“I am optimistic that current vaccines will remain quite useful,” he wrote, adding he is eager to get the vaccine himself. “However, I do expect that as SARS-CoV-2 continues to evolve, eventually, it may be necessary to update vaccines.”
Concerns now may be ‘overblown’
Susan Weiss, a microbiologist at the University of Pennsylvania, said it’s too early to worry about either variant. “I just feel like it’s way overblown,” she said of public concerns.
There are 30,000 spots in the genome of the SARS-CoV-2 virus that could be mutated, Weiss said, so even the 23 mutations found in one of the new variants make only a tiny difference in the virus that causes COVID-19.
Mutations are simply what happens when a virus uses host cells to make copies of itself. Copying errors can occur with each replication, and they are more likely to take place with RNA viruses like SARS-CoV-2, which don’t have mechanisms to correct these genetic spelling mistakes.
The family of viruses to which SARS-CoV-2 belongs, called coronaviruses, mutate far less often than viruses like the flu, where new vaccines are needed every year, or HIV, which has so far been impossible to vaccinate against.
Weiss said she’s not even convinced yet that these variants are more transmissible. Most of the studies conducted so far have focused on the epidemiology of the variant, finding that the British one is more transmissible because it now causes more infections than earlier strains.
But there are other explanations for why it could be winning out, including human behavior, she said. If people with the British variant visited family for Christmas, for example, that version might have spread faster.
“Separating out changes in behavior from changes in the virus seems to be kind of difficult,” Weiss said. “Everyone seems to accept that it’s spreading faster but I don’t know that that’s necessarily correct.”
New strains leave ‘less room for error’
Essential aspects of the virus remain unchanged, despite the mutations, said Stephen Morse, who studies emerging infectious diseases at the Columbia University Mailman School of Public Health.
“The physical properties of the virus haven’t changed,” he said. Its size is the same, as is its ability to be killed with detergents and disinfectants.
“So, the precautions we’ve been using up until now are going to work as well as they have up until now,” Morse said. “The thing is we’re obviously going to have much less room for error.”
Unfortunately, those precautions haven’t worked very well in the U.S. and elsewhere, largely because people have not been willing or able to wear masks without fail and avoid others, particularly indoors. More than 4,000 Americans died Thursday of COVID-19, and nearly 275,000 additional people were diagnosed, according to a USA TODAY analysis of data from Johns Hopkins University.
In SARS-CoV-2, mutations may particularly arise in people who lack the ability to fight it off, said Akiko Iwasaki, a Yale University immunobiologist. Inside the body of someone who’s immune system struggles to contain the virus, it has an opportunity to mutate around the person’s weak defenses, she said.
They may then pass the mutated version onto someone else. The more the virus spreads, particularly among immunocompromised people, the more likely mutations will appear.
One way to prevent this, Iwasaki said, is to provide people with COVID who already are immunocompromised – perhaps because of an organ transplant, cancer or autoimmune disease – with a cocktail of antibodies to help them fight off the virus.
The FDA has authorized the use of two antibodies, one of which, from Regeneron, includes two monoclonal antibodies. “We should be giving them monoclonal cocktails,” she said. “The more the merrier.”
Better tracking, more action needed
Dr. W. Ian Lipkin, an epidemiologist at Columbia, said his main fear about the variants is they will render monoclonal antibodies ineffective.
Unlike vaccines, which target large areas of the virus’ “spike” protein, monoclonal antibodies are directed at one precise spot on the virus. If that spot is changed through mutation, an antibody directed against it might not work, Lipkin said.
“The monoclonal antibodies, their days are numbered,” he said.
It remains difficult to study variants and their dangerousness, said Iwasaki. The gold standard test, as Pfizer-BioNTech did, is to see whether the blood of vaccinated people can neutralize the virus. But it’s not easy for scientists like herself to obtain blood and viral samples.
She thinks the federal government should have created a centralized effort to follow changes in the virus by collecting and testing samples, either within government agencies like the CDC, or among international scientists. “I haven’t seen any organized effort at this point,” Iwasaki said.
Preventing the spread of the virus, including its new variants, will require more aggressive actions, such as careful mask wearing and avoiding contact with others indoors, Iwasaki said.
“We have to up our game,” she said.
Ken Alltucker contributed to this report.
Contact Karen Weintraub at kweintraub@usatoday.com.
Health and patient safety coverage at USA TODAY is made possible in part by a grant from the Masimo Foundation for Ethics, Innovation and Competition in Healthcare. The Masimo Foundation does not provide editorial input.