New variants of SARS-CoV-2, the virus that causes COVID-19, are circulating globally and in the U.S. The emergence and rapid spread of at least three coronavirus variants has intensified the need to further understand how the novel coronavirus mutates and what this indicates for vaccine effectiveness.
Three variants of the virus circulating that cause COVID-19 are:
- B.1.1.7, which was first identified in the United Kingdom, spreads more easily and quickly than other variants. This variant was detected in the U.S. in December 2020.
- B.1.351 emerged in South Africa and shares some mutations of B.1.1.7. This variant appeared in the U.S. at the end of January 2021
- P.1 originated in Brazil and contains a set of additional mutations that may affect its ability to be recognized by antibodies. It was first detected in the U.S. at the end of January 2021
These three variants first discovered in Britain, South Africa and Brazil are worrisome because of combinations of mutations that make them more contagious. Among the three main variants, the B.1.1.7 variant from the U.K. “is more highly transmissible and that translates into the fact that it could take less virus and less time in the same room with an infected person for someone to become infected themselves,” said Dr .Mira Irons, AMA Chief Health and Science Officer, during a recent episode of the “AMA COVID-19 Update” about COVID-19 variants and vaccines
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“Hundreds of cases of the variant first detected in Great Britain have been found,” she said. She noted that Anthony Fauci, MD, has said “the U.K. variant might become the dominant strain in the U.S. by March.” Public health experts suspect these emerging coronavirus variants could lead to a spring surge if people become lax in protecting themselves or stop using the public health measures that are recommended.
Viruses continually mutate and the right combination of particular mutations can escape vaccination. But studies are raising concern that first-generation Covid-19 vaccines don’t work as well against a mutant that first emerged in South Africa as they do against other versions circulating around the world.
Major manufacturers also are developing experimental variant vaccines, just in case. Covid-19 vaccines produce antibodies that recognize the spike protein that coats the coronavirus. When the virus mutates, sometimes the spike protein is changed in key areas so the vaccine-produced antibodies have a harder time recognizing it.
The Pfizer and Moderna vaccines are made with a piece of genetic code called messenger RNA that tells the body how to make some harmless copies of the spike protein that then train immune cells. To update the vaccine, they can simply change the original genetic code with mRNA for the mutated spike protein.