Dado Ruvic | Reuters
Omicron BA.4 and BA.5 sub-variants are circulating at low levels in several countries in South Africa and Europe, according to the World Health Organization. The two subvariants of the highly contagious strain of Covid-19 have been detected in Botswana, South Africa, Germany and Denmark, among other countries, WHO’s technical director for Covid-19, Maria Van Kerkhove, said on Thursday. BA.4 and BA.5 do not appear to be more contagious or deadly than the original omicron mutation so far, but that could change as more cases are detected, she added. Van Kerkhove stressed the need to maintain “robust” genome surveillance systems that would allow countries to track and analyze the two subvariants, as well as previous versions of the omicron. “It’s still early. What we need to make sure of is that we continue to have the ability to follow, the ability to share, and the ability to analyze, so that we can answer questions like this,” Van Kerkhove said during a briefing. to the WHO. which was broadcast live on the organization’s social media platforms. Her remarks come days after the WHO said it was pursuing dozens of cases of BA.4 and BA.5, in addition to previous omicron variants such as BA.1, BA.2, BA.3 and BA. 1.1.
A new wave of cases
It also appears as the more contagious BA.2 sub-variant advances in many parts of the world, fueling a new wave of Covid cases after the unprecedented rise caused by the original omicron variant, BA.1, during the winter. BA.2 is now the dominant global strain. In the US, it accounts for about 85% of new cases sequenced and is even more prevalent in the Northeast region of the country, where it accounts for about 92% of newly sequenced cases, according to Centers for Disease Control and Prevention. The oldest BA.4 sample was collected in South Africa on January 10, but data show that “genome accumulation” and the geographical spread of the subvariant are more recent, according to a report by the UK Health Security Agency. last week. . As of April 8, South Africa had reported 41 cases of BA.4, Denmark reported three cases, Botswana reported two, and England and Scotland reported one each. “Although the total number of genomes is small, the apparent geographical spread suggests that the variant is being transmitted successfully,” the UK Ministry of Health said in a report. The report also said that 27 BA.5 sequences were reported on April 8, all of which were reported in South Africa between February 25 and March 25. But the Botswana Ministry of Health said on Monday that it had identified both BA.4 and BA. 5 cases among fully vaccinated people between the ages of 30 and 50, Reuters reported. WHO has begun tracking BA.4 and BA.5 because they have new mutations “that need to be further studied to understand their impact on the potential for immune escape,” according to Reuters. Both subvariants have additional mutations in the peak region, part of the virus that is used to invade human cells, and unique mutations outside that region, according to a WHO report released Wednesday. Such mutations are associated with “potential immune escape features”, the report said.
Subvariant XE