Nearly six months after another variant of the Omicron coronavirus was identified in South Africa, two mutant branches are causing a surge in COVID-19 cases again, according to Ewen Callaway, a Nature contributor..

Several studies published last week show that variants known as BA. 4 and BA. 5 may partially evade the immune defenses that have recovered from early forms of Omicron, as well as vaccinated.

“We are definitely entering a SARS-CoV-2 renaissance in South Africa, and it appears to be driven entirely by BA variants.. 4 and BA. 5,” says Penny Moore, a virologist at the University of the Witwatersrand in Johannesburg, South Africa.. “We are seeing a crazy amount of infections. In my lab alone, six people are being treated.”.

However, scientists say it is not yet clear whether BA will be caused. 4 and BA. 5 Significant spike in hospital admissions in South Africa or elsewhere. The high level of herd immunity provided by previous waves of Omicron infection and vaccination could mitigate much of the damage previously caused by SARS-CoV-2.

Moreover, the growth in the number of BA. 4 and BA. 5, as well as other Omicron offshoots in North America, could mean SARS-CoV-2 waves are starting to become predictable. “These are the first signs that the virus is developing differently” compared to the first two years of the pandemic, when variants of the virus seemed to appear out of nowhere, says Tulio de Oliveira, a bioinformatician at Stellenbosch University in South Africa, who led one of the studies..

By analyzing viral genomes from clinical samples, de Oliveira and colleagues found that BA. 4 and BA. 5 appeared in mid-December 2021 and early January 2022, respectively. Since then, these lines have been increasing in prevalence and currently account for 60-75% of COVID-19 cases in South Africa.. The researchers also identified similar variants in more than a dozen other countries, mostly in Europe..

Based on the rise in BA cases. 4 and BA. 5 in South Africa, which currently averages almost 5,000 per day, de Oliveira's team calculated that these variants are spreading faster than the earlier Omicron BA.

According to evolutionary biologist Tom Wenzelers of the Catholic University of Leuven in Belgium, “Evaluating all the data, it seems that a significant new wave of infection is bound to come.”.

Jesse Bloom, an evolutionary virologist at the Fred Hutch Research Center in Seattle, Washington, agrees that BA. 4 and BA. 5 Spread Faster Than Other Omicron Lines. “What is still unclear is why they are more contagious,” he says.. Second, these Omicron variants elude antibodies better, allowing them to infect people with prior immunity..

Ability BA. 4 and BA. 5 elude immunity, though not fatal, but enough to lead to another wave of a pandemic. While most researchers agree that these Omicron variants are unlikely to cause more severe disease than seen in the previous wave, especially in vaccinated individuals.

It is likely that the evolution of SARS-CoV-2 could become similar to that of other respiratory infections such as the flu.. Accordingly, periodic waves of infection should be expected in the future, the researchers agree..

However, scientists caution that the Delta variant has not completely disappeared, and as global immunity to Omicron and its growing family increases, the Delta descendant may return.. Whatever their source, new variants seem to pop up every six months..

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About half a billion cases of COVID-19 infection have been recorded in the world, according to an interactive map of the spread of coronavirus from the Center for Systems Research at Johns Hopkins University.