10 Things to Know About the New COVID Strains
Mutations from the UK, Brazil, South Africa, as well as newly identified variants in the U.S., remind us how we aren’t out of the pandemic woods yet.
A full year into the pandemic—can you believe it's already March again?—and, thankfully, there is new hope in the form of vaccines. But there are also some pressing new problems. The coronavirus continues to ravage the world as mutating strains emerge, some of them more transmissable and deadly. Which means this crisis is by no means behind us.
Three variants of COVID-19—from the UK, Brazil, and South Africa—are spreading rapidly and causing a lot of concern in the scientific community. And the U.S. is seeing new variants, too. We have a lot of questions about them, so we turned to two epidemiologists for answers. Here’s everything you need to know about the new strains of COVID and what makes them worth paying attention to.
1. One strain, first documented in the UK last fall, is spreading fast.
This new COVID strain, or B.1.1.7, as it is officially called, was first discovered by scientists through genetic sequencing—a procedure used to track how viruses change and mutate—in September 2020 in southeast England. It has now become the predominant COVID strain in the UK. It’s also spreading quickly around the world and has been confirmed in 46 U.S. states, accounting for 2,400 confirmed cases here so far (though that number reflects the cases experts know about—not, in all likelihood, how many cases there truly are). On February 8, a new study revealed that the UK variant is doubling in cases here in the U.S. every 10 days.
2. Another variant emerged in South Africa around the holidays, and a third was found in Brazil.
On December 18, after news had come out about the UK strain, South Africa announced that it was dealing with a similar new variant of COVID-19, called B.1.351. (Unfortunately, by February 28, a total of 53 cases were detected in 16 states, so it has made its way here.) A different strain from Brazil, called P.1, was discovered on January 12 after having circulated since at least December. This variant has now been confirmed in a total of 10 cases in five states.
In theory, these fast-evolving viral mutations aren't all that surprising. “Viral mutations are quite common and expected,” says Saskia Popescu, Ph.D., infection prevention epidemiologist in Phoenix and member of the Federation of American Scientists COVID-19 task force. As a living organism, a virus naturally adapts and changes—just like the flu mutates each year. In fact, COVID variants have already existed for months, helping scientists track the spread of the virus across the world.
3. All three mutations appear to be more transmissible than earlier strains of the virus.
The reason these three strains are garnering widespread interest is because they appear to be spreading more due to "changes on the spike protein that binds to the human respiratory cell,” explains Shira Doron, M.D., infectious disease physician and hospital epidemiologist at Tufts Medical Center in Boston. “That’s worrisome. It binds more tightly than other normal variants, suggesting that it has an easier time entering the cell.” Again, in the case of the UK variant, 2,400 cases may not seem like a huge amount, but that’s only the number scientists have confirmed—and by the time you’re reading this, that number may have gone up exponentially. The South African and Brazilian variants also appear to be more transmissible based on their rapid spread throughout those countries.
4. All three strains might be more deadly (for different reasons).
The symptoms and course of illness for all three strains so far appear to be the same as other forms of COVID. But there is emerging evidence that both the B.1.351 (South Africa) and P.1 (Brazil) variants might be more deadly because they appear not to respond well to our available treatment options. (Find out why below in question #8.)
Again, mutations of the S protein also make all three strains more transmissable. And, simply put, more cases means more hospitalizations and likely more deaths.
On January 22, UK Prime Minister Boris Johnson said in a media briefing that there is "some evidence that the new variant—the variant that was first identified in London and the southeast [of England]—may be associated with a higher degree of mortality." Experts in the country are still studying and tracking the B.1.1.7 mutation closely. Johnson urged the public to continue to mask up and stay home when possible to minimize risk of transmission.
5. There have also been a few U.S-based strains recently identified.
On January 13, a pre-print study (meaning one that has yet to be peer-reviewed) from researchers at Southern Illinois University Carbondale found a newly identified variant of COVID in the U.S., called 20C-US, also through genetic sequencing. This strain is independent of the UK and South Africa variants but appears to be just as transmissible. The study’s authors estimate that this variant likely emerged early in the pandemic to now account for half of all COVID cases in the U.S., and suggest it continue to be closely monitored to study its characteristics.
On January 19, researchers in Ohio identified two variants, called COH.20G/501Y and COH.20G/677H, which have likely been circulating since December or prior. No specifics are yet known about these variants, but their genetic makeup is similar to the UK and South Africa strains, meaning they also might be extra contagious.
Yet another variant, this one called CAL.20C, has been discovered in Southern California. A January 20 pre-print study noted that this strain likely emerged in November 2020 and now accounts for about one-third of COVID cases in the state. It is independent of all other recently identified variants, but it does share some of the those same mutations that make as strain more transmissible.
On February 23, researchers from Caltech identified a new COVID variant spreading in New York City. It's called B.1.526 and appears to have emerged in the NYC area around November 2020. B.1.526 accounts for around 25% of coronavirus cases in the New York region, according to the pre-print study. It has similar characteristics to the South African and Brazilian strains, so scientists are concerned that it may be more deadly and potentially make vaccines less effective, although more research needs to be done. Another group at Columbia University has also been studying B.1.526. They released a pre-print study on February 25 confirming the discovery of this variant, though they found it in a lower percentage (12%) of COVID cases tested in the region.
6. You wouldn’t necessarily know if you had a new strain or an older form of COVID.
Most, but not all, of the existing rapid and point-of-care (PCR) tests work at detecting the newer UK, South Africa, and U.S.-based strains. (On January 8, the FDA released an alert about three different brands of PCR tests that might give a false negative in the case of the UK variant.) But not all can tell the difference between the new variants and older strains of COVID—they might just provide a positive result.
Dr. Doron explains that sometimes PCR tests can provide a clue as to whether someone has a new variant, based on the specific parts of the genetic code they are built to detect. But to know for sure whether you had the UK, South Africa, Brazil, or U.S.-based strain, scientists would need to do genetic testing. For most of us, not an option.
7. Evidence suggests that some variants may make our current crop of vaccines less effective...
On January 25, Moderna announced in a statement that it believes its vaccine will protect against all existing forms of COVID, though the company is also working on developing a booster shot for the South Africa and UK variants as a precaution. A February 8 study in Nature found that the Pfizer vaccine protects against the UK and South Africa strains of COVID-19. In addition, a February 17 report from the New England Journal of Medicine confirmed the Pfizer vax protects against the South African variant.
Johnson & Johnson's single-shot adenovirus vaccine, which was approved by the FDA on February 27, has shown a range of efficacy results against moderate and severe disease in different countries, the company announced, ranging from 72% in the U.S. to 66% in Latin America and 57% in South Africa. Experts suspect that the dominance of the new strains in Brazil and South Africa may be responsible for lower efficacy of the vax in those countries. And, despite the reduced efficacy of the J & J vaccine in South Africa, that country is now choosing it over AstraZeneca's candidate, which appears to provide even less protection against the South African strain, according to mid-February reports.
AstraZeneca's candidate is a two-dose viral vector vaccine. It was approved in the UK in January but has been in clinical trials for months, stalling the FDA from granting a similar approval in the U.S. It appears to reduce transmission of COVID-19 by 67%, according to one study, something that had not yet been proven in any other COVID vaccine research. (Scientists believe the same will hold true with all approved vaccines.) But, again, it appears to be less effective in protecting against the South Africa strain.
In addition, another vax in the running (but not yet FDA-approved) from Novavax has shown 89.3% efficacy for protecting people from the disease yet is only 49.4% effective in South Africa, the company reported, with nearly all the infections it analyzed there involving the B.1.351 variant.
8. …and antibody treatments may not work against the South African and Brazilian variants.
Concerningly, research is emerging to suggest that monoclonal antibody treatments (laboratory-produced proteins that mimic the immune system to help fight off harmful antigens, including viruses), may not work as well against the South Africa and Brazil variants of COVID. A January 13 study in Cell Host & Microbe suggests that the South Africa mutation may be able to evade detection by the antibodies in the immune system, due to its specific mutation in the spike protein that binds to the respiratory cell.
9. These strains likely won’t change our vaccination schedule.
A few public health experts have floated the idea of vaccinating everyone one time, rather than holding back enough existing shots for people to get second doses of Pfizer or Moderna. (Now that J & J's single-shot vax is approved with 100 million doses reportedly available by June, perhaps fewer will push for it.) The thought behind this is that some level of immunity might be conferred to a large swath of the public this way, thereby potentially thwarting the spread of newer strains. But Dr. Doron warns that this goes against the way clinical trials were developed and conducted. “We didn’t study the effect of one dose,” she says. “We don’t know how much infection it prevents, and we don’t know how long [immunity] lasts.” After months of promises by health experts and drug companies that these vaccines would go through every level of vetting, she thinks it is simply too risky to deviate from the approach that was studied, saying, “We could never support that as experts.”
10. The same strategies can be used to protect yourself against the new strains.
“The routes of transmission haven't changed, so our intervention strategies are still effective and needed now more than ever,” Popescu says. Wearing a mask, washing your hands, and maintaining six feet of distance from others all help keep the new strain at bay. The Pfizer and Moderna vaccines aren't fully effective until two weeks after the second dose, and the Johnson & Johnson vaccine takes 28 days to confer full immunity.
Though these variants may be more transmissible, they are not transmitted any differently than other existing strains of the virus. “It doesn’t change how your respiratory secretions travel through the air, [and] it doesn’t change how likely your spit is to go through a mask,” Dr. Doron says. “It’s just, when you come into contact with virus, how much is needed or how likely is it that that virus is going to make you sick?” To prevent infection, now is the time to keep doing what we’ve all been doing for months now: quarantining, limiting contact with others, and avoiding non-essential travel.
With or without these new variants, we are still neck-deep in this pandemic, and we all need to keep doing our part. “We’re losing thousands of people a day—we absolutely need to put an enormous amount of effort and prioritization on vaccinating as many people as possible,” Dr. Doron says. “This is time to do more than you’ve ever done before to prevent the spread of infection.”
New COVID Variants: Centers for Disease Control and Prevention. (2021.) “New COVID Variants.” cdc.gov/coronavirus/2019-ncov/transmission/variant.html
U.S. Map of Variant Cases: Centers for Disease Control and Prevention. (2021.) “Variant Cases.” cdc.gov/coronavirus/2019-ncov/transmission/variant-cases.html
UK Strain, Scientific Brief: Centers for Disease Control and Prevention. (2020.) “Interim: Implications of the Emerging SARS-CoV-2 Variant VOC 202012/01.” cdc.gov/coronavirus/2019-ncov/more/scientific-brief-emerging-variant.html
New U.S. Strain of COVID: bioRxiv. (2021.) “Emergence and Evolution of a Prevalent New SARS-CoV-2 Variant in the United States.” biorxiv.org/content/10.1101/2021.01.11.426287v1
Pfizer Vaccine Efficacy Against Mutations: bioRxiv. (2021.) “Neutralization of N501Y mutant SARS-CoV-2 by BNT162b2 vaccine-elicited sera.” biorxiv.org/content/10.1101/2021.01.07.425740v1
FDA Warning About False Negatives: Food and Drug Administration. (2021.) “FDA Issues Alert Regarding SARS-CoV-2 Viral Mutation to Health Care Providers and Clinical Laboratory Staff.” fda.gov/news-events/press-announcements/fda-issues-alert-regarding-sars-cov-2-viral-mutation-health-care-providers-and-clinical-laboratory
South Africa Variant, Antibody Treatment: bioRxiv. (2021.) “Comprehensive mapping of mutations to the SARS-CoV-2 receptor-binding domain that affect recognition by polyclonal human serum antibodies.” biorxiv.org/content/10.1101/2020.12.31.425021v1