What Is a COVID Variant? Here's What to Know About the New Variants From the UK, South Africa, US, and More
Multiple newly reported COVID-19 variants are infecting people in various parts of the world and more than a dozen states, and everybody wants to know if these new variants pose a larger threat. At this stage, there's still a lot to figure out, but scientists are working to answer the most pressing questions—in particular, whether the new variants increase the risk of more serious illness and whether they affect the efficacy of the current COVID-19 vaccines.
What is a variant—and is it the same as a strain?
First, it helps to understand some of the terminology. Although many people refer to the new variants as new "strains" of the virus, this isn't quite accurate. "SARS-CoV-2 is the strain within the family of coronaviruses associated with the disease COVID-19," infectious disease expert Leonard Krilov, MD, from NYU Langone Hospital, Long Island, tells Health. "Other coronavirus strains are the original SARS virus, the Middle Eastern respiratory (MERS), and a number of coronavirus strains associated with mild upper respiratory infections."
A strain is a virus with specific biological properties, Dr. Krilov explains. And within a strain, a virus changes (mutates) regularly as it replicates. However, unless those mutations lead to changes in fundamental properties and/or the clinical disease they cause, they don't constitute a new strain. "In fact, it appears the SARS-CoV-2 is mutating 2-6 times slower than most RNA viruses in nature," Dr. Krilov says.
When a particular virus has accumulated an unusual number or combination of important mutations, this is known as a variant. "A variant of concern (VOC) is one where we are concerned that the mutations confer the variant with greater infectivity or ability to cause more severe infections," Supriya Narasimhan, MD, chief of infectious diseases at Santa Clara Valley Medical Center, Santa Clara County, California, tells Health. "A variant of interest (VOI) is a term when we note an unusual emergence of a certain variant...but we are not yet sure if the variant is clinically significant. It means we are studying and monitoring its pattern further."
Right now, there are four newly ID'd COVID variants of concern—here's a closer look at each of them, in order of when they were identified.
UK COVID variant: B.1.1.7
First detected in the United Kingdom in September, the B.1.1.7 variant is highly prevalent in London and southeast England. It's also been detected in more than 50 other countries, including the US and Canada, as well as 29 states to date per the Centers for Disease Control, from New York to California to Alaska, Florida, Georgia, Texas, Massachusetts, and South Carolina. Former FDA commissioner Dr. Scott Gottlieb has predicted that B.1.1.7 will be the dominant variant in the US by March.
Scientists have established that B.1.1.7 is somewhere between 50% to 70% more transmissible than other variants. While there's currently no evidence that it causes more severe illness or increased risk of death, researchers on the UK government's New and Emerging Respiratory Virus Threats Advisory Group found it may increase the death rate by 30% to 40%. However, their sample size was small and they stressed that more research is required.
South African COVID variant: B.1.351
Another variant , B.1.351, which shares some mutations with B.1.1.7, was first detected in South Africa in late December. There have been some cases reported in other parts of Africa as well as in Europe, Asia, and Australia, but not yet in the US. According to researchers in South Africa, this variant is about 50% more transmissible than earlier versions.
Manaus, Brazil COVID variant: P.1
In mid-December, the P.1 variant was first detected in samples from Manaus in the Amazonas state in northern Brazil. It was also identified in four travelers from Brazil when they were tested during routine screening at Haneda airport outside Tokyo, Japan. P.1 is now known to widely circulate in Brazil's Amazonas state, and it's also been observed in the Faroe Islands and South Korea. On January 25, the first known appearance in the US was reported, in a person who recently returned to Minnesota after traveling to Brazil.
The P.1 variant shares some mutations with B.1.351, and a report from Brazilian researchers said it is "potentially associated with an increase in transmissibility or propensity for reinfection of individuals."
United States COVID variants: COH.20G/501Y and COH.20G/677H
A preprint study published on January 19 in the journal bioRxiv confirmed two stateside COVID-19 variants, known as COH.20G/501Y and COH.20G/677H. Since the end of December, these variants have been identified in multiple Midwest and Western states, including Michigan, Utah, Texas, and Wyoming. COH.20G/501Y now accounts for the majority of all COVID-19 cases in the Columbus, Ohio area. COH.20G/501Y and COH.20G/677H possess mutations that increase their infectiousness.
Will the vaccines protect against the new variants?
This is where it gets complicated. Scientists are testing vaccines against the mutations and variants, and results should be available in the next few weeks. "Early studies suggest that vaccination leads to a polyclonal immune response, meaning the virus variants will need to accumulate many mutations—all in the spike protein, which the vaccine targets—to evade immunity," Dr. Narasimhan says.
In a press release published January 25, Moderna said their vaccine retains neutralizing activity against both B 1.1.7 and B.1.351. The press release also stated that the company is developing a variant booster vaccine, should it be required. Likewise, preprint studies have shown that the Pfizer vaccine retains its ability to neutralize the B.1.1.7 variant.
Dr. Krilov notes that the P.1 variant contains three mutations in the spike protein (among others). "This variant is associated with changes in the antigenic profile that may impact the ability of antibodies, either from prior infection or vaccine, to kill or neutralize this variant," he explains. "There is some preliminary laboratory testing data suggesting that even if it takes higher levels of antibodies to neutralize this variant, the mRNA vaccines still generate high enough levels of antibodies to still be effective, but this will need to be monitored." In other words, even if a particular mutation reduces the vaccines' effectiveness slightly, the shots should still do their job. As for the US variants, right now there's no evidence that they will be resistant to the current COVID-19 vaccines
A bigger concern about the new variants is that increased transmissibility leads to more rapid spread. "That, in turn, may further overwhelm hospitals and the healthcare system—and lead to more adverse outcomes before sufficient numbers of people can be vaccinated to control the spread," Dr. Krilov says. "There would also be implications for businesses, schools, and additional possible shut-downs."
While the scientists get on with studying the new variants, we need to play our part, too. "With a more infectious virus, we don't know if our existing tools—masks, physical distancing, and hand-washing—are just as effective against this variant as they were in an identical scenario with the regular strain," Dr. Narasimhan says. So it's more important than ever to stick to these habits, and follow any additional guidelines that may be released by the Centers for Disease Control and Prevention (CDC) and your local health department.
The information in this story is accurate as of press time. However, as the situation surrounding COVID-19 continues to evolve, it's possible that some data have changed since publication. While Health is trying to keep our stories as up-to-date as possible, we also encourage readers to stay informed on news and recommendations for their own communities by using the CDC, WHO, and their local public health department as resources.
To get our top stories delivered to your inbox, sign up for the Healthy Living newsletter