New Covid strain: How worried should we be?

Viruses change all the time. Mutations are a natural part of virus evolution. Viruses naturally evolve as they move through the population. A mutated virus sounds instinctively scary, but to mutate and change is what viruses do. Most of the time, it is meaningless. Most viral mutations have no impact. Occasionally it hits on a new winning formula.

So, what is mutation of virus? Viruses have all their genetic material in something called RNA (ribonucleic acid). When viruses infect, they attach to the cells of the person, get inside them, and make copies of their RNA, which helps them spread. If there is a copying mistake, the RNA gets changed. Scientists call this change “mutations”. These changes take place randomly. But when a virus changes randomly, infects people and begins to spread, that virus strain becomes more common. The new strain gets a new name.

There is no clear-cut evidence the new variant of coronavirus - is able to transmit more easily, cause more serious symptoms or render the vaccines useless. But concerns are growing over the new strain of coronavirus identified in the United Kingdom. The strain is concerning because it has so many mutations – nearly two dozen – and some are on the spiky protein that the virus uses to attach and infect cells. That spike is what the current vaccines target.

It becomes a bigger worry to scientists when a virus mutates by changing the protein on its surface to help it escape from the drugs or the immune system. Emerging evidence” suggests that may be starting to happen with the new virus.

It is a warning sign nevertheless, although it can be interpreted in two ways: The virus could have mutated to spread more easily and cause more infections; and secondly, how the virus has mutated. It will take experiments and studies in the laboratory to figure out what is going on and if this variant really is a better spreader than all the others.

Soon mass vaccination will put a different kind of pressure on the virus because it will have to change in order to infect people who have been immunized. If this does drive the evolution of the virus, we may have to regularly update the vaccines, as we do for flu, to keep up.

Vaccines do produce wide-ranging responses by the immune system beyond just those to spike the protein. Vaccines stimulate a broad antibody response to the entire spike protein, so it is anticipated that their efficacy will not be significantly hampered by mutations. The possibility that new strains will be resistant to existing vaccines is low, but not inexistent. That is because a lot of genetic changes in the genetic code, not just one or two would be needed to undermine a vaccine. But vaccines may be needed to be fine-tuned over time as changes take place.

However, the new strain doesn’t change the public health advice: Wear masks, wash hands and maintain social distance.