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Covid variants inevitable as long as the virus continues to spread, doctors say – TribLIVE

The virus that causes covid-19 has mutated over and over again, and experts say new variants will continue, in part because of the nature of the virus, but also because a large portion of the population chooses not to be vaccinated.

“Should we expect more variants? The answer is yes, ”said Dr. Mohamed Yassin, Director of Infection Control at UPMC Mercy. “How many? Probably too many. There will be a lot of them.”

The very nature of the coronavirus, he said, makes it susceptible to mutation.

There are two main types of viruses, Yassin explained: DNA type and RNA type. Each time the DNA virus splits, make an exact copy of itself. This process of perfect copying does not occur in RNA viruses, which means that there is a chance for change every time the virus replicates. The virus that causes covid-19 is the RNA virus. So is the flu.

“It’s no different than what we see with the flu virus every year,” said Dr. Carol Fox, Excel’s chief medical officer. “It changes often, and that’s why we have to get vaccinated against the flu every year: because there are different variants.”

Whether the variant will be heavier or portable is largely a matter of chance, Yassin said. Viruses can often be changed or reengineered in the lab, he said, “but in nature these changes are accidental.

“It’s almost impossible to know what the next strain will be,” he said. “Will it be more virulent or less? I don’t think we can know that. ”

A potential exacerbation of the problem, Yassin said, is the fact that many people have not been vaccinated.

Across the country, just under 222 million people are fully vaccinated – about two-thirds of the population. According to the Centers for Disease Control and Prevention, about 47% of them received a single dose.

In Pennsylvania, about 66% of the population is fully vaccinated, and 32% have a single dose dose, according to the state Department of Health.

The proportion of people vaccinated in Allegheny County is higher than in the entire state: 73% are fully vaccinated and almost 38% have a single dose, the data show. In Westmoreland County, the numbers are lower than across the state: 60% are fully vaccinated and 30% have received a supplement.

“If you don’t have a lot of (viruses) around, you’ll have a much lower chance of mutations and new variants – that’s absolutely true,” he said.

He said it was an important part of the public health message that still accompanies the pandemic.

“It’s not all in the person or you or me. It’s about us, “he said. “So, yes, if we all don’t get an infection, if we all have a lot less activity because of vaccination, the mutation rate will certainly decrease.”

Variants over time

At least five variants of the virus were identified, some of which had their own subvariants. Currently, omicron and its subvariants are the dominant strain circulating the world. The first case of Covid-19 attributed to the omicron variant was discovered in the United States in early December, and proved even more portable than its highly contagious predecessor, the delta.

The omicron variant was subsequently referred to as the variant of concern, which the World Health Organization defines as a variant that shows an increase in transmission or harmful changes in the covid-19 epidemiology; increased virulence; or is less affected by public health measures such as vaccination and mitigation measures.

Omicron led to a large increase in the number of cases in late 2021 and early 2022. Although it was found to cause less severe disease than past variants, its rapid and easy transmission meant an influx of hospitalizations and an increase in deaths.

A number of omicron subvariants have since been discovered, including BA.2 and BA.2.12.1. In early June, the CDC estimated that subvariants BA.4 and BA.5 accounted for about 13% of new cases – more than 7.5% a week earlier, according to Yale Medicine.

Before omicron, there was a delta variant. It was first identified in Indiana in late 2020, according to Yale Medicine, but its rise in the U.S. did not begin until the fall of 2021, leading to an increase in cases after months of decline. Some studies have suggested that the delta variant is 80% to 90% more transmissible than previous variants, and has been found to cause much more severe disease in those vaccinated.

Alpha, beta and gamma variants circulated in 2020, each with varying degrees of greater portability. At the time, the World Health Organization named them variants of interest.

The World Health Organization has also named a number of what they call variants of interest: variants that show predictable changes and cause significant transmission in the community. Among them were epsilon, zeta, eta, theta, jota, kappa, lambda and mu.

“We didn’t call those variants worrying, but they were variants that were more transferable,” said Dr. Kevin McCarthy, an assistant professor of molecular genetics and biology at the University of Pittsburgh. “What we saw as immunity began to build up in populations, viruses could make mutations and begin to cross part of that immunity.”

How exactly this happens, he said, is not entirely clear.

“The virus will adapt as it passes through hundreds of millions and billions of people – continuing to infect and then re-infect humans,” said McCarthy, who is a member of the Pitt Vaccine Research Center. “So whatever the virus can do to make it better, it will eventually figure out how to do it.”

It’s a process that experts still don’t fully understand, he said.

It is possible – but not certain – that some mutations occur in people with weakened immune systems who have permanent infections. As the body tries to fight the virus, McCarthy explained, the virus tries to replicate. To achieve that goal, the virus can be developed to infect cells more effectively, he said, and antibodies created during the disease can even be developed and avoided.

He likened it to playing the lottery every week.

Every time the virus replicates, it buys a lottery ticket. Most of the time nothing comes of it, he said, “but from time to time someone wins the Mega Millions.”

‘We will live with this’

As has been the refrain since the pandemic began more than two years ago, experts say there is no way to know exactly what the future holds.

“It’s a million-dollar issue,” McCarthy said.

What he does know is that there is no indication that covid-19 is disappearing.

“We’ll live with this,” he said. “What it looks like, I don’t think we’re sure yet.”

McCarthy said it is unclear whether the virus will be as seasonal as the flu has been in years past, but there are likely to be ups and downs dictated by human behavior.

He said that at best there would be one or two dominant variants at once, as opposed to the countless mutations that appear in the circle. That, he said, would make it harder to find ways to deal with the virus in the long run. For now, companies are working on covid vaccines that are on the same principle as flu vaccines because they target three or four strains in a single dose.

Fox said she believes Covid-19 will eventually look more cyclical.

“I think the hope, or what you’d expect to see, is if those peaks and valleys are getting smaller,” she said. “Instead of … high and low falls, the variations will continue, but they will look more like small flashes.”

It depends on human behavior, she pointed out. She said that is why colds and flu cases usually start in the fall when children return to school and when more people are indoors for longer without open windows.

“It has to do with what’s going on in our environment,” she said. “There are more opportunities for the spread of germs, viruses and bacteria.”

Yassin also said he believes the virus could take on a more seasonal appearance, but noted that the real future of covid disease, hospitalization and death depends on vaccination.

“The vaccination rate in the United States is really much lower than in other Western countries,” he said. “It puts us in a more vulnerable position. We have had, like the United States, so many cases, we have had so many deaths. I wish we could convince more people to get their vaccine for themselves and the community. ”

Megan Guza is a writer for Tribune-Review. You can contact Megan at 412-380-8519, [email protected] or via Twitter .


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