(WHTM) — The World Health Organization has identified five COVID-19 variants of concern, with omicron being the latest addition to the list. But how do virus variants develop in the first place?
Viruses often mutate as they replicate, and if those mutations are beneficial for the virus, they may stick around and spread.
“When viruses replicate, they reproduce their RNA, which is their genetic code, and they do it very inefficiently, so there are mistakes made frequently in that replication,” explained Dr. Joseph Kontra, chief of infectious diseases at Penn Medicine Lancaster General Health.
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These mistakes — or mutations — can have harmful, neutral, or even beneficial effects for the virus. The beneficial mutations may help the virus spread or replicate more efficiently, giving the virus variant with that mutation an advantage over other strains. (Think Darwin’s “survival of the fittest” concept.)
The delta COVID-19 variant has long been the most concerning strain of the coronavirus in the U.S. It is more transmissible than previous strains, meaning it can infect more people and spread more quickly. This is just one example of how incidental mutations that benefit the virus can become widespread.
“Each sequential variant that has developed has been more contagious than the one before, and that is to the advantage of the virus,” Kontra said. “In the setting of people being vaccinated and therapeutic agents and antibodies being available, the quicker a virus can replicate, the more likely it is to survive.”
The recently identified omicron variant appears to have an especially high number of mutations in its spike protein, but the exact effects of these mutations are still being studied.
It is possible that future mutations of the coronavirus will continue becoming more contagious. In a previous interview with abc27, Casey Pinto, assistant professor of public health sciences at the Penn State College of Medicine, proposed another idea for the future of the virus.
Pinto’s theory: “It will mutate to not be as deadly.” The coronavirus requires a human host to replicate, and viruses “want” to live and replicate, so viruses that quickly kill their hosts are at a disadvantage.
Pinto and others expect that COVID-19 will never completely go away. Instead, they think the virus will become one of the illnesses commonly impacting people along with diseases like the flu. But also like the flu, the coronavirus could still be deadly for a portion of the people who catch it.
“The worst flu year was about 60,000 deaths, and COVID has already killed 600,000 people in the U.S. So it’s 10 times as deadly,” Pinto said. “So even if it were cut in half…it would still be five times as deadly as flu.”
Pinto’s outlook is fairly optimistic compared to another concern about the variants — that they will mutate to be able to evade the COVID-19 vaccines. The vaccines still offer protection against the variants that have been identified in the U.S. so far, but experts don’t yet know whether they’ll be as effective against future strains.
“Three or four months down the road, if a variant develops that’s resistant to the vaccines that we have, then we’re sort of back to square one, we’re back to April of 2020 when things were exploding with the COVID virus,” Kontra said.
The trick to preventing the development of new variants is limiting the number of people COVID-19 can infect. The virus needs to use human cells to replicate, and the variants develop during the replication process.
If the virus infects fewer people, it replicates less frequently, and, therefore, mutations that could benefit the virus happen less often.
“You have to eradicate the infection itself, and the only way to do that at this point, besides the things we’ve been doing — masking, social distancing — is to get vaccinated,” Kontra said. “The more people we get vaccinated, the slower and less likely variants will be to develop.”
Dr. John Goldman, infectious disease specialist at UPMC Pinnacle, reiterated this idea in an email.
“While we can’t be sure of the number of variants that will develop in the future, we can do our part to shut down the virus by getting vaccinated. If we can stop the current virus, we will see fewer variants develop,” Goldman wrote.