COVID-19: Will variants evolve to be less deadly? Here is what experts have to say

Scientists routinely warn that delaying COVID vaccines could lead to the creation of possibly more deadly strains. Other viruses, on the other hand, have changed through time to become less lethal, historically. So, what are the forces of evolution that influence a virus's fate? The pandemic has spawned a slew of catchphrases, but two have been increasingly popular in recent weeks, Variants will develop to be milder and COVID will become endemic. 

Flu or influenza is frequently cited by those who claim that viruses become less lethal with time. Both the influenza viruses that caused the 1918 Spanish flu and the 2009 swine flu pandemics changed to become less harmful over time. The 1918 virus, on the other hand, is likely to have been more lethal before becoming milder. Other viruses, such as Ebola, have evolved over time to become more lethal.

While many people believe the virus will become less hazardous as it evolves, William Hanage, an associate professor of epidemiology and a member of the CCDD faculty, emphasised that it is not guaranteed. "There’s a widespread public perception that viruses become less dangerous over time because they evolve to avoid harming the hosts they rely on for transmission," he said, in an article published by Harvard school of public health. He further added that the virus might become more or less dangerous at any time.

Sars-CoV-2 does not appear to be becoming milder over time. The Omicron strain appears to be less severe than the Alpha or Delta versions, but both produced more severe sickness than the original Wuhan strain. Importantly, viral development is not a one-way street. Omicron did not evolve from Delta, and Delta did not evolve from Alpha — viral evolution is far more random and unpredictable.

These [variants of concern] are not going one from the other, and so if that pattern continues, and another variant pops out in six months, it could be worse,” said Prof David Robertson, head of viral genomics and bioinformatics at the University of Glasgow’s Centre for Virus Research, The Guardian reported.

What about the possibility of COVID-19 becoming endemic? 

Endemic refers to a disease that is always present, but whose infection rates are predictable and do not spiral out of control. The Guardian reported, according to Stephen Griffin, a virology associate professor at the University of Leeds, Smallpox, Polio, Lassa fever, Malaria, Measles and Mumps are endemic, although vaccination is required in some cases. Endemic does not imply that anything becomes toothless.

As more people gain immunity to Sars-CoV-2 or recover from infection, the virus's ability to cause severe sickness may decrease. However, it is possible that it will evolve once more. The good news is that as more of the world's population is vaccinated, the risk of the virus evolving decreases - but we're still a long way off, according to the experts. Even in the United Kingdom, there are substantial numbers of unvaccinated people, and it's uncertain how long supplemental vaccinations will provide protection.

(With inputs from agencies)