The World Health Organization (WHO) said in its latest weekly report on Covid-19 that nearly 1.5 million new cases of the malady and over 2,000 deaths had been confirmed globally. The WHO also issued an alert over the appearance of a new strain in several countries.
However, the UN agency warned that the new document had limited credibility since not all countries were testing people with symptoms or conducting constant surveillance of the coronavirus genome. In this scenario, the WHO urged its Member States to maintain their established Covid-19 infrastructure and not dismantle it.
The increase in cases has been linked to sublineages of the Omicron variant gaining predominance in virus transmission.
Currently, WHO is tracking three sub-lineages in its variant of concern category: XBB.1.5, XBB.1.16, and EG.5, better known as Eris. It also has 7 other sublineages on the radar, including BA.2.86, which some experts already informally call Pirola.
As of August 23, only nine sequences of the BA.2.86 variant from five countries have been uploaded to the GISAID platform. To date, no deaths among the cases detected with Pirola have been reported to WHO. Switzerland and Thailand have mentioned detecting this sublineage in sewage samples.
This variant with many mutations has appeared in many places now, at a time when genomic and sewage surveillance is greatly diminished worldwide, said scientist Eric Topol, founder and director of the Scripps Translational Research Institute.
The Pirola sublineage was detected in Israel, Denmark (3 individuals), the United Kingdom, the United States (in 2 individuals, one from Japan), and South Africa. It is safe to say that the presence of BA.2.86 is widespread throughout the world at this time, Topol stated.
It is yet unknown how infectious Pirola may be, which is key to knowing how this will play out. If we look at the early days of Omicron in November 2021, it already declared its high transmissibility in southern Africa, he added.
In Denmark, where genomic surveillance is strong, another week has passed with no new BA.2.86 [was] detected, so that’s encouraging, he went on. But it’s possible that there is more transmission globally than has been detected so far because our surveillance has been plummeting.
Pirola (BA.2.86) stands out in the variant family tree because of how much it has morphed. It has more than 30 mutations in its Spike protein, the cell-crossing part of the virus that vaccines train the body to fight. Experts believe that antibodies generated by infection with earlier variants will have difficulty recognizing the new sublineage.
Meanwhile, the EG. 5 variant became the dominant strain in the United States and has already arrived in Argentina, with the first cases registered in Córdoba and the Autonomous City of Buenos Aires (CABA).
The disease is serious in older adults and people with health problems. Otherwise, it poses a threat no greater than that by any other circulating variant of interest.
It’s a growing concern, but it doesn’t seem to be much different than what’s already been circulating in the United States for the last three or four months. So I think that moderates my concerns about this variant, at this point, said Andrew Pekosz, a professor of Molecular Microbiology and Immunology at the Johns Hopkins Bloomberg School of Public Health.
In this scenario, the risk posed by EG. 5 is estimated to pose a low public health risk globally, according to the WHO.
The variant was identified in China in February and was first detected in the United States in April. It is a descendant of the XBB. 1.9.2 subvariant of Omicron and its mutation helps it evade antibodies developed by the immune system in response to previous variants and vaccines, which might be why EG. 5 became the dominant strain worldwide and Covid-19 cases are again on the rise.
According to Pekosz, that mutation could mean that more people are susceptible to the virus, as it can better evade immunity. In any case, Eris, as it is also known, does not appear to have any new capabilities in terms of its degree of contagiousness, its symptoms, or its likelihood of causing serious disease.
Experts are more concerned about other emerging variants making the virus more transmissible through combining mutations dubbed FLip because of how they place two different amino acids. While these variants only make up a small proportion of current Coronavirus cases, they could trigger a further increase in infections over the weeks, it was explained.
I am very concerned about the pace of SARS-CoV-2 evolution, said Trevor Bedford, professor in the division of vaccines and infectious diseases at the Fred Hutchinson Cancer Center. No single variant has caused a lot of havoc, but the overall accumulation of these mutations is having a significant impact, he noted.
