How low vaccination rates can lead to new coronavirus variants

All viruses, including the new coronavirus, evolve over time.

“When someone gets infected with the virus, the virus enters its body, enters the cells, and begins to make copies of itself,” he explains. Dr. Mary Beth Sexton, Associate Professor of Infectious Diseases, Emory University School of Medicine. “And every time the virus copies itself, an error can occur.”

Sexton compares this to transcript input — you have to make some typos.

“It’s the same with viruses,” she says. “When copying itself, it makes mistakes. Most of these mistakes are not a problem, but others that actually make the virus more contagious, more serious, treatments and vaccines do not work well, etc. There can be mistakes that can cause problems, and that’s when we start to worry. “

Thousands of variants have occurred since SARS-CoV-2 was first identified in 2019. Most of these mutations have little or no effect.

However, depending on where the mutation occurs in the genetic material of the virus, the characteristics of the virus, such as the transmission and severity of the disease, can be affected.

WHO currently classifies variants into three main categories. That is, variants of interest, variants of concern, and variants with significant consequences.

“These basically tell us how much we should be worried about and how quickly we need to act to protect ourselves and our community,” says Sexton. ..

According to WHO, the mutant strain (VOI) of interest is predicted or known to affect infectivity, disease severity, antigenic escape (such as vaccine avoidance), or changes in diagnostic or therapeutic capacity. There are changes.

VOI also usually causes an increase in the rate of illness and outbreaks in certain areas.

“But usually, the mutant strains of interest do not have large, widespread cases across the United States or other countries,” explains Sexton.

A Variant of Concern (VOC) meets all the criteria for VOI, but it spreads more easily, causes more serious illness, or responds well to current tests, vaccines, or treatments. There is evidence that it will not.

“Variant of concern not only needs to be monitored, but it also needs to act fairly quickly to prevent it from moving on to the next category of mutants with significant consequences,” he explains. .. Gary Whittaker, PhD, Professor of Virology, Cornell University.

We have not yet seen variants with significant consequences, but this category means that the virus evades vaccines, diagnostic tests, or treatments. There will also be more serious illnesses and hospitalizations.

“Basically, a variant with significant consequences causes a big problem,” says Sexton.

There is still much to be learned about Omicron, but several factors make Omicron a cause for concern.

“One is that there is some evidence that it can be more contagious,” says Sexton. “It is a rapidly increasing number of COVID cases in South Africa, as well as an increasing proportion of cases they have identified as Omicron.”

I’m also concerned about the number of mutations Omicron has.

“There are many changes, or many typos and errors compared to the original virus,” explains Sexton. “And to see it, it begins to worry people about how well our vaccines and treatments work, but we still need a lot of data.”

Low vaccination rates can add coronavirus variants in two ways. One is related to the whole population and the other is related to the individual.

A virus can mutate each time it replicates, because an error can occur each time the virus copies itself.

“In order to reproduce and make those mistakes, they must spread and infect new people,” Sexton explained. “Therefore, if there is a fully vaccinated population, the virus does not spread very well. Therefore, there is no chance of raising these errors.

“But with a lot of unvaccinated people, there’s a lot of spread,” she continued. “And when you have a lot of spread, the virus is copying itself, and when you are copying itself, you mutate.”

At the individual level, if a person is infected with SARS-CoV-2, vaccination reduces the chances of the virus mutating.

“We’re starting to learn that people who have breakthrough infections, whether vaccinated or COVID, don’t seem to be contagious for a long time.” Says Sexton.

“The reason is that even if the virus can get into it even a little, it will eventually start a reaction in the immune system developed by the vaccine and get rid of it sooner.”

In unvaccinated people, it stays in the body much longer, giving more time to copy itself.

“Therefore, infected unvaccinated people are a better incubator for making variants, as the virus copies itself more internally and the unvaccinated population spreads it,” says Sexton. increase.

For these reasons, it is important for everyone to be vaccinated against COVID-19 and get a booster shot when they are eligible, Whittaker says.

Other precautions we have come to rely on, such as wearing masks, washing hands, and increasing social distance, can also have a significant impact.

“Obviously, if you feel sick, don’t go out and interact with others,” said Whittaker. “And if you feel good and have access to regular rapid diagnostics, that’s certainly a big part of how to deal with this.”

It is also essential to address vaccine inequality around the world that is causing delays in vaccination and deployment in low- and middle-income countries.

by Vaccine Equity Global DashboardOnly 8% of people in low-income countries, founded by the United Nations, WHO and Oxford University, have received at least one COVID-19 vaccine as of December 8.

This is compared to 65% of high-income countries who started vaccination of their population two months ago on average in low-income countries. Access to vaccines in low-income countries remains surprisingly low.

“This is the definition of being together,” says Sexton. “You will see the virus spread rapidly in areas where the population has not been vaccinated. Therefore, this is from a poorly vaccinated and disadvantaged country over and over again until it is fixed. Is also a setting for the continued emergence of variants. Really, the whole world will have access to the vaccine. “