Covid, what is the BA.2.86 variant
It has attracted the attention of the World Health Organization for its 36 mutations. At the moment, nothing suggests that we can go back to the critical months of the pandemic but its spread across 3 continents, including Europe, reminds us that Covid-19 will remain a public health problem in the foreseeable future. Facts, predictions and comments on variant BA.2.86
We hadn't thought about it for months but now that even the latest anti-Covid rule has fallen in recent days, the pandemic is now a distant memory. From the United States, however, comes the news of a new lineage of the SARS-CoV-2 virus, called BA.2.86, the same one that until recently was called BA.X. At the moment, according to information from the Centers for Disease Control and Prevention (Cdc), it has been detected in the United States, Denmark and Israel.
The peculiarity and the aspect to pay attention to, writes Roberta Villa, scientific journalist with a degree in medicine and surgery, is that "it has many new mutations".
As the experts recall, however, nothing suggests a new wave similar to that of the pandemic peak, but it is nonetheless a fact that reminds us that Covid-19 will remain a public health problem in the near future and that if the pandemic is behind us, the disease has not completely left us.
WHAT WE KNOW ABOUT THE NEW VARIANT BA.2.86
The new BA.2.86 lineage was identified yesterday by the US CDC and the World Health Organization (WHO) said it had classified it as a "variant under monitoring" due to the large number of mutations it carries.
CDC is tracking a new lineage of the virus that causes COVID-19. This lineage is named BA.2.86, and has been detected in the United States, Denmark and Israel. CDC is gathering more information and will share more about this lineage as we learn it.
— CDC (@CDCgov) August 18, 2023
WHO has designated #COVID19 variant BA.2.86 as a 'variant under monitoring' today due to the large number of mutations it carries.
So far, only a few sequences of the variant have been reported from a handful of countries.
https://t.co/3tJkDZdY1V
— World Health Organization (WHO) (@WHO) August 17, 2023
The mutations compared to the currently dominant variant XBB.1.5 are in fact 36 and, as explained by the director of Diagnostic Microbiology of the Houston Methodist, S. Wesley Long, the new lineage "refers to a previous branch".
BA.2.86, which descends from BA.2, took a similar evolutionary leap to the one that gave rise to Omicron.
“Interestingly, the last direct descendant of BA.2 (BA.2.85) was designated on September 30, 2022, i.e. 10.5 months ago,” 'variant hunter' Ryan Gregory of the Department of Biology wrote in X. integration of the Canadian University of Guelph. “That's not to say there aren't many descendants of BA.2. In fact, almost everything in circulation now has BA.2 as an ancestor, including the globally dominant recombinant XBB lineage."
On the possible origins of the variant, Gregory then said: “With so many mutations, not descended from any more recent variant of the now disappeared BA.2, the BA.2.86 variant must have evolved for a long time outside the general population. Most likely within a person with a chronic infection, or perhaps a non-human reservoir species."
NOT JUST BAD NEWS
The crux of the matter is that the large number of mutations raises concerns that BA.2.86 may escape the immune responses we have developed from previous infections or through vaccinations.
Early analyses, said Jesse Bloom, a virologist at Fred Hutchinson Cancer Center, indicate that the new variant "will have equal or greater evasion than XBB.1.5 from antibodies elicited by pre-Omicron and first-generation Omicron variants." Furthermore, for the virologist, "it will also have a further antigenic advantage compared to the XBB variants now that a large part of the population has been exposed to these variants".
"But to be successful – says Bloom -, the BA.2.86 variant should combine this antigenic advantage with an intrinsic transmissibility at least close to the current XBB variants".
As also stated by the WHO, only a few sequences of the variant have been reported so far from a handful of countries, which currently makes it impossible to say that it has high transmissibility and for this it is necessary to continue monitoring.
Also for Gregory, BA.2.86 "could be a problem if it starts showing signs of growth, but it is not at all clear if it can compete with the XBB variants that have been evolving for months now".
THE INCREASING SPREAD OF THE VIRUS IN THE UNITED STATES
However, in the United States, although the average hospitalization rate is not a perfect measure, between June and July the number of hospitalizations increased by about 17% and other signs, such as wastewater analyses, also point to a greater prevalence of the virus.
VACCINES (NEVER ENOUGH) UPDATED
In the event of a new wave, a potential problem could be the absence of specific vaccines for this variant since, no matter how much we try to speed up its updating, it is impossible to predict the mutations that the virus may present. Those arriving in the autumn, in fact, are designed to hit the Omicron XBB.1.5 subvariant, but they also seem to offer a certain protection against EG.5 (Eris), another variant – daughter of XBB.1.9.2 – which has spread rapidly in recent months and is predominant in the United States.
This is a machine translation from Italian language of a post published on Start Magazine at the URL https://www.startmag.it/sanita/covid-cose-la-variante-ba-2-86/ on Fri, 18 Aug 2023 10:18:11 +0000.