Variants of viruses occur when there is a change or mutation to the viruss genes. Ray says it is the nature of RNA viruses such as the coronavirus to evolve and change gradually. Geographic separation tends to result in genetically distinct variants, he says.

Mutations in viruses including the coronavirus causing the COVID-19 pandemic are neither new nor unexpected. Bollinger explains: All RNA viruses mutate over time, some more than others. For example, flu viruses change often, which is why doctors recommend that you get a new flu vaccine every year.

Is there a new coronavirus mutation?We are seeing multiple variants of the SARS-CoV-2 coronavirus that are different from the version first detected in China, Ray says.

He notes that one mutated version of the coronavirus was detected in southeastern England in September 2020. That variant, now known as B.1.1.7, quickly became the most common version of the coronavirus in the United Kingdom, accounting for about 60% of new COVID-19 cases in December. It is now the predominant form of the coronavirus in some countries.

Different variants have emerged in Brazil, California and other areas. A variant called B.1.351, which first appeared in South Africa, may have the ability to re-infect people who have recovered from earlier versions of the coronavirus. It might also be somewhat resistant to some of the coronavirus vaccines in development. Still, other vaccines currently being tested appear to offer protection from severe disease in people infected with B.1.351.

B.1.351: A Coronavirus Variant of Concern?One of the main concerns about the coronavirus variants is if the mutations could affect treatment and prevention.

The variant known as B.1.351, which was identified in South Africa, is getting a closer look from researchers, whose early data show that the COVID-19 vaccine from Oxford-AstraZeneca provided minimal protection from that version of the coronavirus. Those who became sick from the B.1.351 coronavirus variant after receiving the Oxford-AstraZeneca vaccine experienced mild or moderate illness.

The B.1.351 variant has not been shown to cause more severe illness than earlier versions. But there is a chance that it could give people who survived the original coronavirus another round of mild or moderate COVID-19.

Researchers studying placebo (non-vaccine) recipients in the South African COVID-19 vaccine trial by Novavax compared subgroups of participants who did or did not have antibodies indicating prior COVID-19. Those who did have the antibodies most likely were infected with older variants of SARS-CoV-2. They found that having recovered from COVID-19 did not protect against being sickened again at a time when the B.1.351 variant was spreading there.

Will the COVID-19 vaccine work on the new variants?Ray says, There is new evidence from laboratory studies that some immune responses driven by current vaccines could be less effective against some of the new strains. The immune response involves many components, and a reduction in one does not mean that the vaccines will not offer protection.

People who have received the vaccines should watch for changes in guidance from the CDC [Centers for Disease Control and Prevention], and continue with coronavirus safety precautions to reduce the risk of infection, such as mask wearing, physical distancing and hand hygiene.

We deal with mutations every year for flu virus, and will keep an eye on this coronavirus and track it, says Bollinger. If there would ever be a major mutation, the vaccine development process can accommodate changes, if necessary, he explains.

How are the new coronavirus variants different?There are 17 genetic changes in the B.1.1.7 variant from England, Bollinger says. Theres some preliminary evidence that this variant is more contagious. Scientists noticed a surge of cases in areas where the new strain appeared.

He notes that some of the mutations in the B.1.1.7 version seem to affect the coronaviruss spike protein, which covers the outer coating of SARS-CoV-2 and give the virus its characteristic spiny appearance. These proteins help the virus attach to human cells in the nose, lungs and other areas of the body.

Researchers have preliminary evidence that some of the new variants, including B.1.1.7, seem to bind more tightly to our cells Bollinger says. This appears to make some of these new strains stickier due to changes in the spike protein. Studies are underway to understand more about whether any of the variants are more easily transmitted.

Are coronavirus variants more dangerous?Bollinger says that some of these mutations may enable the coronavirus to spread faster from person to person, and more infections can result in more people getting very sick or dying. In addition, there is preliminary evidence from Britain that some variants could be associated with more severe diseases. Therefore, it is very important for us to expand the number of genetic sequencing studies to keep track of these variants, he says.

Bollinger explains that it may be more advantageous for a respiratory virus to evolve so that it spreads more easily. On the other hand, mutations that make a virus more deadly may not give the virus an opportunity to spread efficiently. If we get too sick or die quickly from a particular virus, the virus has less opportunity to infect others. However, more infections from a faster-spreading variant will lead to more deaths, he notes.

Could a new COVID-19 variant affect children more frequently than earlier strains?Ray says that although experts in areas where the new strain is appearing have found an increased number of cases in children, he notes that the data show that kids are being infected by old variants, as well as the new ones. There is no convincing evidence that any of the variants have special propensity to infect or cause disease in children. We need to be vigilant in monitoring such shifts, but we can only speculate at this point, he says.

Will there be more new coronavirus variants?Yes. As long as the coronavirus spreads through the population, mutations will continue to happen.

New variants of the SARS-CoV-2 virus are detected every week, Ray says. Most come and go some persist but dont become more common; some increase in the population for a while, and then fizzle out. When a change in the infection pattern first pops up, it can be very hard to tell whats driving the trend changes to the virus, or changes in human behavior. It is worrisome that similar changes to the spike protein are arising independently on multiple continents.

Are there additional COVID-19 precautions for the new coronavirus mutations?Bollinger says that as of now, none of the new coronavirus variants call for any new prevention strategies. We need to continue doing what were doing, he says.

Ray concurs: There is no demonstration yet that these variants are biologically different in ways that would require any change in current recommendations meant to limit spread of COVID-19, he says. Nonetheless, we must continue to be vigilant for such phenomena.

Ray stresses that human behavior is important. The more people who are infected, the more chances there are for a mutation to occur. Limiting the spread of the virus through maintaining COVID-19 safeguards (mask wearing, physical distancing and practicing hand hygiene) gives the virus fewer chances to change. It also reduces the spread of more infectious variants, if they do occur.

We need to re-emphasize basic public health measures, including masking, physical distancing, good ventilation indoors and limiting gatherings of people in close proximity with poor ventilation. We give the virus an advantage to evolve when we congregate in more confined spaces, he says.

Regarding coronavirus variants, how concerned should we be?Most of the genetic changes we see in this virus are like the scars people accumulate over a lifetime incidental marks of the road, most of which have no great significance or functional role, Ray says. When the evidence is strong enough that a viral genetic change is causing a change in the behavior of the virus, we gain new insight regarding how this virus works.

As far as these variants are concerned, we dont need to overreact, Bollinger says. But, as with any virus, changes are something to be watched, to ensure that testing, treatment and vaccines are still effective. The scientists will continue to examine new versions of this coronaviruss genetic sequencing as it evolves.

In the meantime, we need to continue all of our efforts to prevent viral transmission and to vaccinate as many people as possible, and as soon as we can. Hopkins Medicine

Originally posted here:
Why does the coronavirus change? - Khmer Times