Over the past few months, new variants of the virus known as SARS-CoV-2 have started to emerge from the U.K. to South Africa and Brazil. Now, scientists are finding that the virus has changed in ways that may affect its ability to spread, potentially resulting in more cases of COVID-19.
A recent, small clinical trial of the Oxford-AstraZeneca vaccine suggested it isn't effective at preventing mild to moderate illness from the South African variant, which accounts for at least 90% of coronavirus cases in the country, but it appeared effective against the original strain.
In late January, Johnson & Johnson announced that its single-shot vaccine is effective in preventing moderate to severe illness but is also less effective against the South African variant. The company applied to the U.S. Food & Drug Administration for emergency use authorization of its vaccine last week. Moderna and Pfizer have both announced that they're developing upgrades to their vaccines that could be used against variants.
Track the spread of the COVID-19 variants: the U.K. variant, the South African variant and the Brazilian variant. This map will be updated regularly.
At this stage, though, one thing remains clear: Existing methods to prevent transmission of COVID-19 are the still the most effective strategies, experts told TODAY. These include masking, or even double masking, maintaining social distance, not socializing unmasked and indoors with people outside your household, regular hand hygiene and getting vaccinated when you're eligible.
Here's what else you need to know about the new COVID-19 strains, from symptoms, to how lethal they are and whether vaccines will work against them.
What is a variant? How does it happen?
While the existence of new variants may be worrisome to the general public, the phenomenon is "not entirely unexpected," Ben Lopman, Ph.D., professor of epidemiology at Emory University's school of public health in Atlanta, told TODAY.
"Viruses spread by replicating themselves ... and that replication process is imperfect," he explained. "The virus makes mistakes sometimes. Most of those mistakes are useless or will kill the virus. Rarely but sometimes, one of those mistakes will be beneficial. It could, for example, make the virus more easy to transmit from person to person by changing its genetics in some way."
The U.K. variant in particular, which research indicates could be more contagious than other strains in the U.S., seems to replicate more efficiently, Lopman said. This could mean that infected people are "actually producing more of the virus or shedding the virus at somewhat higher levels, and that might be what makes it more transmissible," he added.
But viruses acquiring mutations isn't "necessarily a bad thing," Jasmine Plummer, Ph.D., associate director of applied genomics at Cedars-Sinai medical center in Los Angeles told TODAY.
"(Viruses) want to survive," she explained. "It's not in (their) best benefit to keep killing the host, meaning the person. Near the end, (the virus might) figure out a way ... to survive by infecting more people, but the outcome of that infection is hopefully not as severe."
How many strains of COVID-19 are there?
A new strain occurs when a virus goes through one or more mutations that change its behavior in some way, but a variant develops when a virus goes through a mutation of any kind, explained Dr. Patricia Couto, an infectious disease physician at Orlando Health in Florida.
At this stage, she said she believes there's only enough data on the U.K. and Brazil variants to say that they are "for sure" new strains. Researchers also referred to a variant found in California as a strain.
According to Lopman, "there are many variants out there," but a few are concerning because they "appear to be spreading more quickly" and could "possibly (replace) the variants that were previously dominant," he said.
Here's a breakdown of the concerning COVID-19 variants, including the U.K. variant, South African variant and Brazilian variant, and what to know about each:
The U.K. strain, called B.1.1.7, was first reported in the U.S. in late December, and it spreads more quickly and easily than other variants, according to the Centers for Disease Control and Prevention. A CDC report from earlier this month found it could become the dominant strain in the U.S. as early as March. As of Feb. 9, there were 932 confirmed cases of this variant in 34 U.S. states. It's also spreading at high levels in Denmark and Scandinavia, Lopman said.
South African variant
This variant, known as B.1.351, emerged independently from the U.K. strain but shares some of its mutations, according to the CDC. Data indicates that it first emerged in South Africa in October and has since spread to other countries, including the U.S. In late January, the CDC confirmed two cases in South Carolina, and CDC director Rochelle Walensky told TODAY at the time that it had already reached the point of community spread. This variant could also make reinfection more likely; a vaccine study in South Africa found new infections with a variant in 2% of people who'd already had another version of the coronavirus. So far, it's also been detected in Maryland and Virginia, and according to Lopman, it does seem to spread more easily than other strains in the U.S.
The Brazilian strain, P.1, was first detected in mid-January in travelers to Japan from the Amazonas state of Brazil. It appears to contain mutations that raise concerns about its transmissibility and potential for reinfection, according to the CDC. Manaus, the largest city in the Amazon region, saw a surge in cases in December, despite 75% of the population already having been infected by October. Three cases of this variant have been reported by the CDC in the U.S. in Minnesota and Oklahoma.
U.S. variants in California, Ohio
A new strain known as CAL.20C now accounts for half of COVID-19 cases in Southern California, according to research from Cedars-Sinai medical center in L.A. To detect the strain, researchers initially looked at 10,000 COVID-19 samples from the state as far back as March and found the earliest sample of the strain in July, Plummer, co-author of the research, said. By mid-to-late January, the new strain represented more than 30% of cases in the entire state and more than 40% in Southern California.
As of mid-February, researchers have found CAL.20C in 19 states, Washington, D.C., and six foreign countries. The data at this stage suggests that it could be more easily spread than other strains, but the surge of CAL.20C also coincided with people gathering for holidays, Plummer said.
In Ohio, researchers at Wexner Medical Center in Columbus have discovered two new strains of SARS-CoV-2. Researchers are still tracking the prevalence of both, but they've found that one of the strains became dominant Columbus, Ohio, over three weeks between December and January and suspect it's likely more infectious.
Is the new strain of COVID-19 more deadly?
Whether any of the new COVID-19 strains are more lethal depends on whether you're thinking about the individual patient or the entire population, Dr. Sten Vermund, dean of Yale School of Public Health in New Haven, Connecticut, told TODAY.
"(From) the entire society's point of view, if it's more infectious, more people get infected, then even if it's equal lethality ... you'll have more dead people," he said. "But if you're a doctor and you're trying to take care of a patient, then it may not matter which strain the patient has. Their risk of severe illness and death may be about the same."
U.K. experts reported in January that the U.K. strain may be associated with an increased risk of death compared to other variants, but more research is needed, according to the CDC. There is alsoemerging evidence that the South African strain may be more virulent.
CAL.20C researchers have said it's unclear at this stage whether it leads to more severe illness. Couto added that she thinks it's too early to answer this question about the Brazil variant, which was only discovered last month.
Another factor that can contribute to a new strain or variant being more deadly on a population scale is "how collapsed your health care system is" where it hits, Couto said. "If you have a lot of people that you did not anticipate getting sick at the same time, you will see a bump in mortality, and that doesn't necessarily mean that the virus is more lethal."
Do the new variants have different symptoms?
Currently, none of the new variants have been associated with new or different symptoms, experts told TODAY. Per the CDC, the most common symptoms of COVID-19 include:
- Fever or chills
- Shortness of breath or difficulty breathing
- Muscle or body aches
- New loss of taste or smell
- Sore throat
- Congestion or runny nose
- Nausea or vomiting
Couto also stressed that the new variants and strains also seem to result in the same wide range of illness that's come to be associated with COVID-19.
Will the Moderna and Pfizer vaccines work against them?
The research into the vaccines' efficacy against the variants and strains is ongoing, and Moderna and Pfizer have both released preliminary data on the U.K. and South Africa variants.
A study on Pfizer's vaccine published in Nature on Monday found that it created antibodies that responded to virus samples that had been modified to resemble the U.K. and South Africans variants. The vaccine should protect against both but is slightly less effective on the latter, research suggested.
Moderna announced in late January that a lab study showed "no significant impact on neutralizing titers," which correlate to protection provided by a vaccination, against the U.K. strain. The study did find "a six-fold reduction in neutralizing titers" against the South African variant, but the company said the reduced titer levels are still expected to be protective.
Plummer said her Cedars-Sinai team does not anticipate CAL.20C will evade the vaccines, but they're actively investigating to be sure.
Dr. Anthony Fauci, the nation's leading infectious disease expert,explained on TODAY last week that "if (the variants) do become dominant, we may need to upgrade the vaccine."
He added that it would only take two to three months for these updated doses to become available because the vaccines themselves are "flexible and adaptable. ... We don't need it right now, but we're going in that direction anyway just in case."
Where are the travel bans due to coronavirus variants?
President Biden recently instated travel bans for foreign nationals traveling to the U.S. from countries where the new variants have been reported. These include:
- U.K. and Ireland
- South Africa
According to the CDC, there are also currently travel bans for non-U.S. citizens coming from:
- A large portion of Europe, including Italy, France, Germany, Spain, Scandinavia and more
How might variants effect the timeline for herd immunity?
The fact that these variants exist and are spreading doesn't automatically lengthen the path to herd immunity, Vermund said. But it does make adherence to COVID-19 safety practices that much more influential in the timeline for getting back to normal.
"If we can get broader adherence to prevention messages and drive down (COVID-19) rates, even if we have these new strains circulating, we may be able to control the virus until we can get everybody vaccinated," he said. "If we just flagrantly flaunt the prevention messages, then, sure, the new strains, if they're more infectious, will affect more people and make things bad again."
This article was updated on Feb. 11, 2021.