10 Things to Know About New COVID-19 Variants
The novel coronavirus, SARS-CoV-2, is an easily spread respiratory virus and the cause of the COVID-19 pandemic. As countries around the world are rolling out new COVID-19 vaccines to control the outbreak, scientists are discovering new variants of the COVID-19 virus, including the variant first identified in the United Kingdom. What makes a virus variant, how does it affect the disease, and will the vaccine protect against the U.K. and other variants? Here’s what is known so far.
1. Variants are mutations in the genetic material of the virus.
Virus mutations are normal and expected as the COVID-19 virus gets passed person to person. Another name for a mutation is a variation, so mutated viruses are variants of the original virus. (You may see the term virus “strain” used interchangeably with variant and mutant.) Some mutations help the virus, such as making it more contagious. Variant viruses with these types of mutations will usually persist or even overtake the original virus in circulation. This is happening with the new U.K. COVID-19 variant.
2. The U.K. COVID-19 variant has several mutations affecting the spike protein.
The U.K. variant is named SARS-CoV-2 VOC 202012/01, for ‘Variant of Concern, year 2020, month 12, variant 01.’ Another name for it is B.1.1.7, or B117. This virus has many mutations, some of which change or delete parts of the spike (S) protein—the protein required for the coronavirus to infect cells. This protein is the target of many COVID-19 vaccines.
3. The U.K. COVID-19 variant spreads more easily.
The B117 SARS-CoV-2 variant is widespread in England and now accounts for 6 in 10 COVID-19 infections. It is more contagious—spreading 70% faster, by some accounts. How does that happen? Compared to the original novel coronavirus, the variant virus binds more easily to human cells, accelerating its ability to multiply and cause illness. Coronavirus scientists expect this type of behavior based on the specific changes in the variant. The U.K. variant is spreading in many other countries, including the United States and Canada.
4. The U.K. variant does not appear to cause more severe COVID-19.
So far, COVID-19 caused by variant SARS-CoV-2 is not more severe than COVID-19 caused by the currently circulating virus. The problem is that more COVID-19 cases translates to more people potentially needing medical care in a system that is already stretched thin from the existing rate of infection and people needing intensive care.
5. COVID-19 vaccines are likely to work against the U.K. variant.
There is no evidence to suggest the COVID-19 vaccines won’t be effective, but studies to learn the answer are underway. Researchers are optimistic about vaccine effectiveness against the variant because of how vaccines work.
The available COVID-19 vaccines trigger an immune response and antibodies against the spike protein. The antibodies you build after receiving the vaccine target multiple areas of the spike protein. The spike protein would have to change drastically for the virus to evade the immune system in a vaccinated individual (or in someone with natural immunity due to previous infection), and this is not likely to happen.
A recent, preliminary study shows that one of the concerning mutations (N501Y) in the U.K. variant is neutralized by antibodies from a small subset of Pfizer-BioNTech vaccine recipients. This is more evidence COVID-19 vaccines will be effective against variants containing the N501Y mutation.
The new variant is one reason the U.K. has approved another vaccine, from AstraZeneca and University of Oxford, to vaccinate as many people as quickly as possible. (The U.K. is also currently using the Pfizer-BioNTech vaccine; the U.K. has acquired doses of the Moderna vaccine but has not yet approved it for use.) With widespread vaccination, researchers will be able to quickly determine if the vaccines reduce transmission of the variant—as well as the original virus.
6. The risk of COVID-19 reinfection with the U.K. variant is not known.
Doctors do not yet know if the U.K. variant can infect a person previously infected with the original virus. Reinfection with the original virus is rare, based on available information. From analyzing other COVID-19 variants, scientists know that one of the changes in the U.K. variant helps the virus evade the immune system in some people, so it’s possible reinfection will occur with the U.K. variant. COVID-19 experts monitor possible reinfection cases. They are also tracking COVID-19 cases in people who were vaccinated.
7. Additional testing is necessary to identify and confirm a COVID-19 variant.
The most common diagnostic COVID-19 tests confirm an active infection, but they don’t identify the specific virus variant. If your doctor or the lab that processed your sample needs to know if it contains a variant, they perform an additional step: They analyze the sequence of the virus genetic material for mutations. Knowing the specific variant is usually not necessary, so the genetic analysis is not standard practice. However, starting in January, the U.S. Centers for Disease Control and Prevention (CDC) is requiring each state to submit 10 patient samples biweekly to CDC labs for analysis.
8. The CDC is tracking COVID-19 variants.
Most SARS-CoV-2 mutations are not significant and do not reach the status of “variant of concern.” However, some variants may out-compete the circulating virus strain and become the predominant strain. A COVID-19 variant of concern arose in South Africa. It has some of the same mutations as the U.K. variant, but it is a different variant. Like the U.K. variant, the South African variant does not cause a more severe disease than the current virus circulating throughout most of the world. There is also a new variant of concern in Nigeria. Because viruses like SARS-CoV-2 mutate easily, more variants are likely.
Check the CDC for more information about these and other variants.
9. Current COVID-19 treatments should work against the new variant.
Two antibody therapies for treating COVID-19 are available. Both therapies are monoclonal antibodies that target a specific part of the spike protein. The antibodies should still target the variant’s spike protein and reduce the risk of severe illness. However, it’s possible future strains of the COVID-19 virus may limit how well current (and new) treatments work. If that occurs, drug companies are ready to adapt existing treatments to target new COVID-19 variants.
10. COVID-19 variants may affect rapid antigen test effectiveness.
Most rapid tests detect a SARS-CoV-2 antigen unrelated to the spike protein, so these tests would detect the new U.K. variant (with its multiple changes in the S protein) in a nasal swab of an infected person. Rapid antigen tests work well as a diagnostic tool when a person has a lot of virus in their nasal swab. But a variant that can infect people more easily and at a lower viral load—perhaps below the level of detection of an antigen test—increases the risk of a false negative result.
There has always been skepticism about using rapid antigen tests due to the risk of false negative results in infected asymptomatic people. New variants that can spread easily without a high viral load in the nose may make antigen tests an even riskier choice over molecular tests like PCR for diagnosing or ruling out COVID-19.