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Coronavirus – Do viruses weaken over time? The old theory and the importance of vaccines

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Coronavirus - Do viruses weaken over time? The old theory and the importance of vaccines

As evidence grows that the coronavirus's Micron mutation is less lethal than previous strains of COVID-19, one commonly accepted explanation is that viruses always evolve into less infectious ones over time. However, as experts warn, this theory has been completely refuted.

According to an article in ABC News, Dr. Jess Dawson, the notion that infections tend to become less fatal over time was first formulated by bacteriologist Dr. Thiobald Smith in the late 19th century. His theory of the evolution of pathogens was later called the “law of diminishing infectious power.”

Smith's theory summarized that in order to ensure their own survival, pathogens gradually evolved and stopped killing their hosts. Instead, they cause only a mild infection, allowing people to spread the virus while maintaining contact.

The evolution of viruses is more chaotic

For the past 100 years, however, virologists have found that the evolution of a virus is more chaotic: it looks more like a game of chance than a design product. And in some cases, the viruses become more contagious.

Ongoing survival, spread, and virulence of viruses are associated with evolutionary pressures of many factors, including the number of individuals available for infection, the life span of humans after infection, the immune system response, and the time between infection and the onset of symptoms.

Coronavirus - Do viruses weaken over time? The old theory and the importance of vaccines

It is almost impossible to predict the future of the pandemic

“Unfortunately, this means that it is almost impossible to predict the future of the pandemic, because viruses do not always evolve in a predictable pattern,” Dr. Jess Dawson wrote in an ABC News article, adding that thousands of variants of COVID have been identified, each with unique mutations. . But most new variants appear and then disappear quickly, unable to compete with the dominant variant.

Some variants, however, have clear “benefits to continued survival, such as those that avoid the immune system and spread easily,” said Dr. Abir Hussein of the University of Washington Medical Center.

The severity of Omicron is not unrelated to the wall of immunity

Experts warn that it is important to assess the severity of Omicron in the context of existing immunity through vaccines and previous infections. “It is difficult to determine through Delta or Omicron whether the variants are becoming more or less contagious. “This is because these variants came at a time when we were highly immune to the SARS-CoV-2 virus in some countries,” said Andrew Pekoz, a professor of microbiology.

People who have been vaccinated or recently infected will have milder symptoms if they become ill or re-infected, according to studies. “This is not because the variant is less contagious, but because the immune system was prepared from previous vaccination and infection,” he added.

Experts argue that Omicron should not be considered a less lethal form of COVID. Even though it has a lower mortality rate, the Omicron variant is significantly more contagious, leading to more deaths overall, the report said.

The U.S. Centers for Disease Control and Prevention predicts that 22,000 more people could die from complications of COVID-19 in the next two weeks. People who are not vaccinated are at a much higher risk, with officials estimating that they are 17 times more likely to be hospitalized and 20 times more likely to die from COVID-19 than people who have been vaccinated.

“The available COVID vaccines provide immunity to a range of variants and continue to be the first line of defense,” said Dr. John Brownstein, chief of innovation at Boston Children's Hospital and an ABC News contributor.

Regarding the future of the pandemic, experts say that new variants may appear in the future, but it will not be easy to predict.

Source: in.gr

Source: politis.com.cy

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