It was widely predicted that SARS-Cov-2, the novel coronavirus, would not be eradicated but would instead establish itself in the community, continue to mutate, and thereby propagate within human populations, only to periodically declare itself in sporadic outbreaks caused by newer and more easily transmissible variants. Most recently, continuing surveillance and genomic sequencing of the coronavirus has thus helped identify Eris (EG.5.1) and Pirola (BA.2.86)- the latest additions to an impressive and growing viral family tree.
BA.2.86, an offshoot of the BA.2 sub-lineage of the Omicron variant of SARS-CoV-2, nicknamed Pirola on the social media platform X (Twitter), was accordingly first detected in Denmark on 26 July 2023, and shortly thereafter in Israel. By 6 September, it had already been identified in eleven countries. It has since travelled around the world, as far afield as Canada, the US, South Africa, and Australia, leading the WHO to label it a “variant under monitoring” on 17 August 2023. Variants differ in the ease by which they spread (transmissibility), their propensity to cause severe infections (virulence), and the effectiveness of protection by vaccines-which reflects their ability to evade existing immunity from previous infection and vaccination. These variants are further classified, in self-explanatory categories, as either variants under monitoring, variants of interest, and variants of concern
Pirola is a highly mutated Omicron sub-variant, with 35 mutations (alterations in amino acid sequences) involving the all-important spike protein, by which the virus attaches itself to host cell receptors in infected people. It was first detected in the UK on 14 August 2023, and was confirmed to have infected 28 residents of a care home in Norfolk in the east of England by 21 August. On 8 September, the UK Health Security Agency stated that there was likely to be community transmission of the virus, while an agency blog on 19 September said “we’re still getting to grips with how the healthcare system responds to the ebb and flow of seasonal cases”. The rise in UK cases in September has been partly attributed to the end of the summer holidays, with the reopening of schools and the return of vacationing workers, along with the onset of cooler weather. Detection of BA.2.86 in wastewater samples suggests an additional route for viral spread.
The symptoms of Pirola overlap with those of seasonal flu and the common cold. These may include a runny nose, sneezing, sore throat, eye irritation, cough, headache, fatigue, fever, loss of taste and smell, diarrhoea, and skin rashes. The diagnosis can thus only be confirmed by a PCR (polymerase chain reaction) test.
The emergence of BA.2.86 has led the four nations of the UK to bring forward the autumn COVID booster vaccine to 11 September 2023, to enable protection for the most vulnerable. The list of people eligible for vaccination includes all people aged 65 years and older; residents in a care home for older adults; those aged six months to 64 years who belong to a clinical risk group; those aged 12 to 64 who are household contacts of immunosuppressed people; those aged 16 to 64 who work in care homes for older adults; and pregnant women. Eligible people will be directly contacted by their local providers and called up for vaccination. The vaccines on offer in the UK are manufactured by four different companies: Pfizer-BioNTech, Moderna, Sanofi/GSK, and Novavax. Meanwhile, a stock of BA.2.86 is being grown at the high-containment facilities at the Vaccine Development Centre at Porton Down in Wiltshire to allow more detailed studies of the virus.
As with other outbreaks, various “experts” have come forward with a range of opinions and predictions, both optimistic and pessimistic. It behoves responsible citizens to and follow and prioritise the recommendations of their national public health authorities, but it is likely that many will chose to be guided by their own beliefs and those that emerge on social media, while complacency and indifference may blunt any official responses to the new variant. It is possible that self-isolation, social distancing, mask mandates, and regular rapid lateral-flow testing may reappear, although it seems most unlikely that any further lockdowns will be required. It is far too early to predict the outcome of this latest outbreak, but the hope is that the large majority of those infected with BA.2.86 will only suffer mild symptoms, which then settle of their own accord.
Ashis Banerjee