AmericaExperts say that the combination of a high transmission rate and a partially immunized community motivates nCoV to adapt.
This is considered the most precarious and risky time in a pandemic. The more the epidemic spreads, the more chances that the virus will develop. Molecular epidemiologist Emma Hodcroft, University of Bern, explains that when an entire population is antibody-free, the virus is not under pressure to evolve.
“But until a part of the community is vaccinated or immune to the circulating virus, this is the moment of danger,” she said.
The new variant also reduces the effectiveness of vaccines and treatments, leading to reinfection in people who have already recovered from the disease. According to scientists, the key to avoiding this situation is social distancing and implementing measures to reduce infection, in addition to boosting vaccination.
“The slower you do both of these, the greater the risk of developing more variations,” said Richard Lessells, infectious disease specialist at the KwaZulu-Natal Research Innovation Platform.
When it spreads from person to person, the virus makes many copies of itself and makes small mistakes. Such errors are incorporated into the genetic code. Some mutations do not affect virus activity. Others, as in British, South African and Brazilian variants, increase the likelihood of transmitting or evading the immune system. Thus, the more infectious the more nCoV generates, the more dangerous the more dangerous variants will stay and dominate.
Vineet Menachery, a virus specialist at the University of Texas Medical School, said: “Each wave of replication is an opportunity for it to combine with a new mutation. If there are few people infected and the replication cycle, the mutation is introduced, too. than”.
If Covid-19 is spread uncontrollably in a community with only partial immunity, the variant will retain beneficial mutations, helping it avoid antibodies or T cells. This phenomenon is called selective pressure. , which helps explain the emergence of some of the variants that arose in the first place and why South African scientists reported abnormally high numbers of reinfection.
Research by Dr. Richard Lessells and colleagues shows that the original B.1.351 variant spread fastest in South Africa’s Eastern Cape province, where many people have acquired and survived Covid-19. The work showed antibodies from a previously infected patient with nCoV were less effective than B.1.351.
According to some experts, this variant has more than 20 mutations, some of which developed in the patient’s body before spreading to others. Many scientists believe a similar situation occurred in the UK when variant B.1.1.7 appeared in December.
Thuc Linh (Follow WSJ)