But they will be more like flu waves.
Almost six months after South Africa has identified another variant of the Omicron coronavirus , with two branches of the mutation again causing a surge in COVID-19 cases, said Ewan Callaway, author of the journal Nature.
Several studies published last week show that variants known as BA.4 and BA.5 may partially evade the immune defenses of those who have early forms of Omicron and have been vaccinated.
“We We are definitely entering the renaissance era of SARS-CoV-2 in South Africa, and it seems to be entirely driven by BA.4 and BA.5, ”said Penny Moore, a virologist at the University of the Witwatersrand in Johannesburg, South Africa. “We are seeing an insane number of infections. In my laboratory alone, six people are being treated. ”
However, scientists say it is unclear whether BA.4 and BA.5 will cause a significant surge in hospitalizations in South Africa or elsewhere. The high level of population immunity provided by previous waves of Omicron infection and vaccination may mitigate much of the damage previously caused by SARS-CoV-2.
Moreover, the increase in the number of BA.4 and BA.5, as well as other branches of Omicron in North America, may mean that SARS-CoV-2 waves are beginning to become predictable. “These are the first signs that the virus is evolving differently compared to the first two years of the pandemic, when variants of the virus seemed to emerge out of nowhere,” said Tulio de Oliveira, a bioinformatics researcher at Stellenbosch University in South Africa who led the study. .
Analyzing viral genomes from clinical specimens, where Oliveira and colleagues found that BA.4 and BA.5 appeared in mid-December 2021 and early January 2022, respectively. Since then, the prevalence of these lines has increased, and they now account for 60-75% of COVID-19 cases in South Africa. Researchers have also found similar options in more than a dozen other countries, mostly in Europe.
Based on the growing number of BA.4 and BA.5 cases in South Africa, which currently averages almost 5,000 a day , de Oliveira's team estimated that these options are spreading faster than Omicron BA.2 before.
According to evolutionary biologist Tom Wenzelers of the Catholic University of Leuven in Belgium, “evaluating all the data, it seems that a new significant wave of infection is sure to come.”
Jesse Bloom, an evolutionary virologist at the Research Center Fred Hutch in Seattle, Washington, agrees that BA.4 and BA.5 are spreading faster than other Omicron lines. “What is still unclear is why they are more contagious,” he said. Second, these versions of Omicron are better at escaping antibodies, allowing them to infect people with previous immunity.
The ability of BA.4 and BA.5 to escape immunity, albeit fatal, is sufficient to trigger another wave of pandemics. Although most researchers agree that these variants of Omicron are unlikely to cause more serious disease than those observed in the previous wave, especially in vaccinated people.
It is likely that the evolution of SARS-CoV-2 may be similar to the evolution of other respiratory infections such as influenza. Accordingly, researchers should expect periodic waves of infection in the future. However, scientists warn that the Delta option has not disappeared completely, and as global immunity to Omicron and its growing family increases, a descendant of Delta may return. Whatever their source, new options seem to appear every six months.
Read also: More than 427 million people worldwide became ill with the COVID-19 pandemic: map
< The world has recorded about half a billion cases of COVID-19 infection, according to an interactive map of the spread of coronavirus from the Center for Systems Research at Johns Hopkins University.
