About six months after South African researchers identified the Omicron coronavirus, two of the game-changing shoots have once again caused an increase in COVID-19 cases. Several studies released last week show that the alternatives – known as BA .4 and BA.5 – are slightly more contagious than previous versions of Omicron and may protect some of the defenses provided by previous infections and vaccines.
“We are definitely starting to re-launch in South Africa, and it seems we are completely driven by BA.4 and BA.5,” said Penny Moore, a gynecologist at the University of the Witwatersrand in Johannesburg, South Africa, whose team learned the opposite. “We are seeing insane numbers of diseases. Just inside my laboratory, I have six sick people. ” However, scientists say it is still unclear whether BA.4 and BA.5 will cause significant increases in hospitals in South Africa or elsewhere. High levels of immunization – provided by previous waves of Omicron infection and vaccination – could dampen the extensive damage associated with new strains of SARS-CoV-2.
Samples of clinics and growth of cases in South Africa
By analyzing viral genes from clinical samples, de Oliveira and colleagues found1 that BA.4 and BA.5 appeared between December 2021 and early January 2022, respectively. Descendants have been growing steadily since then, and currently account for 60-75% of COVID-19 cases in South Africa. Based on the growing number of cases of BA.4 and BA.5 cases in South Africa – now an average of 5,000 per day, from a low of about 1,200 in March – de Oliveira’s team estimates that the variance spreads faster than BA.2
The increase in telecommunications is “a huge advantage”, and is similar in size to the benefits that other fast-spreading varieties SARS-CoV-2 had over their predecessors, says Tom Wenseleers, an evolutionist at the Catholic University of Leuven in Belgium. . “If we put everything together and look at all the details, it looks like a new wave of infection is coming.” The viral protein that causes infection and the main purpose of the immune response. Bloom’s team has previously found that these mutations can help differentiate between antibodies.
Further research suggests that BA.4 and BA.5 increase, at least in part, because of their ability to avoid immune responses. A team led by pathologist Alex Sigal at the Africa Health Research Institute in Durban, South Africa, analyzed blood samples from 39 people who contracted the virus during the first Omicron wave, 15 of whom were vaccinated2.
In laboratory tests, the immune system in these samples failed several times to prevent cells from becoming infected with BA.4 or BA.5 rather than what they had been doing in the final version of the Omicron. However, antibodies produced by vaccinated individuals were more potent in new strains than those derived from humans whose vaccine was caused by a virus with only BA.1. The study was included in medRxiv.
“It is enough to create a problem and cause a wave of infection” – but the exception is unlikely to cause a much worse disease than was seen during previous waves, especially in vaccinated people, Sigal said in a Twitter post. high in South Africa – from fewer than 2,000 people in hospital with COVID-19 in early April – but researchers say it is too early to say whether BA.4 and BA.5 will put too much pressure on health care systems. “Hospitals are empty in South Africa and we have a high number of people who are not vaccinated,” de Oliveira said.
The next wave began in North America
Other parts of North America are also seeing growth of other Omicron sub-lineages with spike protein conversion in other similar areas such as BA.4 and BA.5. One such variant – called BA.2.12.1 – also has the potential to prevent antibodies caused by a previous Omicron infection and vaccination, according to a study by Xie, 3, and the specialist work of pathologist David Ho at Columbia University in New York City.
The emergence of these species suggests that the Omicron genealogy continues to make a profit by eliminating infection, Ho said. “Obviously there are a few holes in Omicron that are slowly filling up with this new variant.” If SARS-CoV-2 persists in this way, its onset may be similar to that of other respiratory infections, such as the flu. In this case, mutations that avoid the immune system of a variety of circuits, such as the Omicron, may be combined with the widespread immersion of human immunity to become important drivers of periodic infections. “It’s probably what we should expect to see more in the future,” Moore said.
Source Journal Reference: Ewen Callaway, Are COVID surges becoming more predictable? New Omicron variants offer a hint, Nature News (2022), doi: https://doi.org/10.1038/d41586-022-01240-x
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