What are the new strains of COVID-19?
New strains, known as variants, of COVID-19 virus seem to be springing up everywhere. Information about variants is increasing and changing every day. The information in this column is based on the best available research at the time it was written (March 9).
One of first variants detected was the Kent, or London, variant, now named B.1.1. (The letter/number names are based on the location of mutations in the virus.) This variant is extremely contagious but does not seem to be more deadly than the original COVID-19. There is a Brazilian variant, called P.1, which is also very contagious. There is a South African variant, B.1.351, which may be resistant to some of the currently available vaccines. There are also several variants that first appeared in the United States. One of these, the California variant, in early research seems to be both more contagious and more deadly.
Why do variants develop?
The process of coronavirus replication, or self-copying, is prone to errors. Each mistake in copying produces a slightly different variant of the virus. Because of these copying errors, new variants are constantly appearing. This is also true for influenza (the flu) and some other viruses, not only COVID-19. Most variants are less dangerous than the original virus, but some are more contagious or more deadly.
Are new COVID variants more dangerous than the original COVID-19 virus?
Many variants are harmless and don’t cause any illness. Some can cause more severe illness than the original virus. Harmless variants are not usually detected because the people who have them don’t get sick, so they don’t get tested.
What makes some variants more easily transmitted, and what are the results of that?
Highly contagious COVID-19 variants have differently shaped spike proteins. The spike protein is the part of the virus that binds to human cells. Having a different spike protein allows these variants to bind to cells faster and more tightly. That means it takes fewer virus particles to infect a person. Tighter binding also lets the virus copy itself more easily, which means a person infected with these variants will make and shed more virus, infecting more other people than someone with the original virus would.
It’s important to understand that even if a variant isn’t more deadly, if it is more contagious it will cause more hospitalizations and deaths because more people will get sick.
When a variant is more contagious, it quickly becomes the most common type of COVID-19 in the area. The Centers for Disease Control (CDC) predicts that the highly contagious Kent variant will become the dominant COVID-19 strain in the US by April.
How can we prevent the development of more COVID-19 variants?
Because new variants develop during viral replication (copying), the only way to prevent them from developing is to prevent the virus from making copies of itself. The only way way to keep the virus from copying itself is by keeping the virus from entering people’s bodies, that is, by vaccinating people against the COVID-19 virus.
Will the currently available vaccines prevent infection with new variants?
That depends on the structure of the new variants. For the variants discovered so far, it looks as like all the three currently available vaccines will give some protection, but might not be as effective as it they are in preventing infection with the original virus. Getting any of the COVID-19 vaccines will either prevent infection or decrease the severity of illness if coronavirus infection does occur.
How many people in the country have to be vaccinated to prevent variants from developing?
We have to think in terms of the world, not just one country. Vaccines know no borders; all efforts to keep viruses geographically isolated have failed. Get vaccinated as soon as you can with whichever vaccine is available. The best vaccine is the first vaccine that’s available to you. Encourage your family and friends to get vaccinated too. Each of us getting vaccine will protect ourselves as individuals. Enough of us getting vaccinated will protect the places where we live and the country as a whole.
Eva Hersh is a family physician. Send your comments and questions to her by email at firstname.lastname@example.org
- Eva Hersh is a family physician. Send your comments and questions to her by email at email@example.com