Viruses are constantly changing, and new versions—called variants—often arise. News of variants of the coronavirus disease 2019 (COVID-19) virus is spreading nearly as fast as the variants themselves.
To learn more about these variants, we talked to Dirk Dittmer, PhD, professor of microbiology and immunology at UNC School of Medicine.
1. When it comes to viruses, variants are common.
A genome, which is an organism’s genetic material, is like an instruction manual for how the organism is made and maintained.
Early on in the COVID-19 pandemic, scientists sequenced the genome of the COVID-19 virus, meaning they determined the detailed chemical building blocks that make up the virus. This information has allowed doctors and scientists to diagnose the virus and create the COVID-19 vaccines.
But like other viruses, the sequence of the COVID-19 virus genome changes, or mutates. The virus that causes COVID-19, called SARS-CoV-2, mutates neither particularly fast (such as the flu virus) or particularly slow. So scientists like Dr. Dittmer continue to study the sequence of newly diagnosed COVID-19 patients so they can watch for those changes.
“So far, all the variants we have seen (at UNC) differ by just one or two amino acids, and they have no particular clinical difference,” Dr. Dittmer says.
Amino acids are the building blocks that link together to form a protein, like the spike protein that is found on the surface of the virus that causes COVID-19, and that is what is responsible for the virus entering its target cell. Over time, some of those building blocks of the COVID-19 virus change—some of these changes have no effects, while others can have drastic effects.
2. Three new variants have raised alarm bells.
Although variants to viruses are common, variants that have several (around 10 or more) changes from the original are uncommon, Dr. Dittmer says. That’s why these new COVID-19 variants are causing concern.
Variants from Britain, South Africa and Brazil have multiple mutations and have changed the virus enough to alter its impact. Early research has found them to be more contagious. For example, the British variant appears to spread more easily, and we are working to understand whether serious COVID-19 disease is more common with this variant.
“More study is needed to know about the impact of these new variants,” Dr. Dittmer says. “So far, what people have found is that these variants are more transmissible, but no one knows exactly why. Whether they are clinically worse, we simply don’t have enough data.”
3. The vaccines are still effective for the new variants.
Researchers have found that the Moderna vaccine still protects against the British variant, but it’s less effective against the one that emerged in South Africa and that shares some of the mutations with a variant that emerged in Brazil, Dr. Dittmer says.
Moderna is now working to create an “emerging variant booster candidate” against the South African variant, known as B.1.351, to determine if it will be more effective against the strain and potentially other future variants.
A recent laboratory study found that the Pfizer vaccine appeared to lose only a small bit of effectiveness against an engineered virus with three key mutations from the new South Africa variant. Its findings are limited because it does not look at the full set of mutations found in the new South African variant, and further research is underway.
Although they may be less slightly effective, these vaccines still work, Dr. Dittmer says.
“If you’re immunized, your immune system will still take care of the U.K. variant just fine,” Dr. Dittmer says. “With the South African variant it’s about fivefold less effective. What remains is, however, still a substantial amount of anti-virus antibodies. You have to remember that an unimmunized person has no protection at all.”
In other words, if you’ve been vaccinated, you still are better protected against South African variant than if you are not.
4. Treatment for COVID-19 remains the same.
No matter which variant you have, you will receive the same treatment for COVID-19. People with mild to moderate symptoms who can rest and drink fluids at home will continue to do so; those with severe illness who require hospitalization will receive medications, oxygen therapy and intubation as needed.
“All the treatments that you get and all the supportive care we provide is the same, so which variant you are infected with doesn’t change your clinical treatment. We don’t treat specific variants at this time,” Dr. Dittmer says.
5. The same safety measures you have been taking protect against the variants.
The same things you have been doing to prevent the spread of the SARS-CoV-2 virus should protect you from the new variants. This means you should wear a mask, wash your hands frequently and stay 6 feet apart from others whenever possible.
“If you look under a big microscope, all the variants still have the same size and have the same physical properties, and that’s why these measures are effective against any variant,” Dr. Dittmer says.
And while getting the vaccine is the best way to reduce your risk, you still need to continue doing those things even after you’re vaccinated. Most Americans won’t be vaccinated for several months, so everyone needs to keep taking precautions to reduce transmission.
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