New variants of SARS-CoV-2 are circulating globally, with early evidence suggesting that they could lead to a more rapid spread of COVID-19 infections. One variant in particular that originally emerged in Britain is reported to be 50% more transmissible and is predicted to become the dominant variant in the United States by springtime. Other variants have since emerged in South Africa and Brazil.
“The fact that a virus makes errors and generates mutations during its replication is actually quite normal,” explains Dr. Mirella Salvatore, an infectious disease specialist and assistant attending physician at NewYork-Presbyterian/Weill Cornell Medical Center. “Not all of these mutations have consequences. However, the variants found in the U.K., South Africa, and Brazil were found to have a considerable number of new mutations at the same time. Some of these mutations are found in the spike protein of the virus, the protein that is particularly important for the virus infection and for the vaccine response. The concern with these new variants is that they may spread more rapidly than previous ones.”
Health Matters spoke with Dr. Salvatore, who is also an assistant professor of medicine and of population health sciences at Weill Cornell Medicine, about these new variants — why they are more contagious and what to do to stay protected.
How do these newly discovered coronavirus variants differ from the original SARS-CoV-2?
We are learning more and more each day, but what scientists have gathered thus far is that these new strains have mutated in a way that makes the virus more transmissible. It appears that these variants can spread more rapidly from person to person — they’re more contagious — and therefore have the potential of infecting more people.
What makes them more contagious?
The mechanism by which these variants have become more contagious is not fully known, but what we do know is that they carry mutations that are localized in the spike protein of the coronavirus. The spike protein is a protein on the surface of the virus; it is what the virus uses to bind to and enter a cell in the body. This is the first step of infection.
Some research on these new variants suggest that some of the mutations on the spike protein make it more efficient at latching onto cells within the body. It is possible that when the binding between the spike protein and a cell is stronger, the virus is more able to infect the respiratory cells and replicates better.
Are these new variants more dangerous, or more deadly?
While they may be more infectious, preliminary research suggests that they are not more deadly. Recent unofficial data released from the U.K. reports a degree of increase in the seriousness of the actual infection. However, these studies have not yet been reviewed, so we need to watch this closely.
Will the COVID-19 vaccine work on these new variants?
Several studies have already shown that the COVID-19 vaccines that have received emergency use authorization in the U.S. do indeed work on the U.K. variant. These are mRNA vaccines that specifically target the spike protein, preventing the attachment to the cell and preventing infection.
I’ve also seen some early (not yet published) studies that suggest that the variants may cause a slight decrease in the antibodies’ ability to fight the variant virus. However, the good news is that the mRNA vaccine platform has already been developed, and it can be quickly readjusted to target a different strain of the virus if we need it to down the road.
Do these new variants affect young people more?
It does not appear that they affect children more than adults. Kids are still less likely to spread the coronavirus than older people. That being said, these new variants appear to be about 30% to 50% more contagious for all age groups.