BA.2.86 is an

Omicron Omicron (, ; uppercase Ο, lowercase ο, ) is the fifteenth letter of the Greek alphabet. This letter is derived from the Phoenician letter ayin: . In classical Greek, omicron represented the close-mid back rounded vowel in contrast to '' o ...

subvariant of

SARS-CoV-2 Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) is a strain of coronavirus that causes COVID-19, the respiratory illness responsible for the COVID-19 pandemic. The virus previously had the Novel coronavirus, provisional nam ...

, the virus that causes

COVID-19 Coronavirus disease 2019 (COVID-19) is a contagious disease caused by the coronavirus SARS-CoV-2. In January 2020, the disease spread worldwide, resulting in the COVID-19 pandemic. The symptoms of COVID‑19 can vary but often include fever ...

. BA.2.86 is notable for having more than thirty mutations on its

spike protein In virology, a spike protein or peplomer protein is a protein that forms a large structure known as a spike or peplomer projecting from the surface of an viral envelope, enveloped virus. as cited in The proteins are usually glycoproteins that ...

relative to BA.2. The subvariant, which was first detected in a sample from 24 July 2023, is of concern due to it having made an evolutionary jump on par with the evolutionary jump that the original Omicron variant had made relative to Wuhan-Hu-1, the reference strain first sequenced in

Wuhan Wuhan; is the capital of Hubei, China. With a population of over eleven million, it is the most populous city in Hubei and the List of cities in China by population, eighth-most-populous city in China. It is also one of the nine National cent ...

in December 2019. It is a mutation of BA.2, itself a very early mutation in the Omicron family. BA.2.86 was designated as a variant under monitoring by the

World Health Organization The World Health Organization (WHO) is a list of specialized agencies of the United Nations, specialized agency of the United Nations which coordinates responses to international public health issues and emergencies. It is headquartered in Gen ...

on 17 August 2023. The variant was nicknamed Pirola by media, although no official sources use this name. Its descendant

JN.1 Variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are viruses that, while similar to the original, have genetic changes that are of enough significance to lead virologists to label them separately. SARS-CoV-2 is the v ...

(BA.2.86.1.1) became the dominating Lineage in Winter 2023/2024.

Affected countries

BA.2.86 was first reported by Denmark and Israel. On 18 August 2023, when only six cases had been reported from four countries (Denmark, Israel, the United Kingdom and the United States), the British healthcare authorities noted that its almost simultaneous appearance in several countries still operating detailed genomic surveillance indicated that it likely already was spreading more widely internationally, a view also shared by other experts. There has been an overall significant decrease in sequencing (ten times as many samples were uploaded to

GISAID GISAID (), the Global Initiative on Sharing All Influenza Data, previously the Global Initiative on Sharing Avian Influenza Data, is a global science initiative established in 2008 to provide access to genomic data of influenza viruses. The datab ...

in August 2022 compared to July 2023), reducing the possibility of tracking variants globally. As of 30 August, 24 cases of BA.2.86 had been detected in Canada, Denmark, Israel, Portugal, South Africa, Sweden, the United Kingdom and the United States (three states, including one detected in an airport in a traveller who had just arrived from Japan). As of 2 September, it had also been detected in wastewater in a number of places where not yet confirmed directly in samples from people, including one U.S. state (earliest U.S. detection in a wastewater sample from late July), Switzerland (where it made up 2% of coronavirus particles in a wastewater sample from one region in early August), Norway, Germany, Spain, Thailand (detection in a wastewater sample from late July) and Hong Kong.

Immunity, contagiousness and virulence

Initially it was feared that BA.2.86 would be able to partially evade earlier immunity. However by November evidence indicated that it was not resistant to existing antibodies. The CDC and WHO assessed that the "public health risk posed by this variant is low compared with other circulating variants".

Moderna Moderna, Inc. ( ) is an American pharmaceutical and biotechnology company based in Cambridge, Massachusetts, that focuses on RNA therapeutics, primarily mRNA vaccines. These vaccines use a copy of a molecule called messenger RNA (mRNA) to carry inst ...

and

Pfizer Pfizer Inc. ( ) is an American Multinational corporation, multinational Pharmaceutical industry, pharmaceutical and biotechnology corporation headquartered at The Spiral (New York City), The Spiral in Manhattan, New York City. Founded in 184 ...

have stated that their

COVID-19 vaccine A COVID19 vaccine is a vaccine intended to provide acquired immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 ( COVID19). Knowledge about the structure and fun ...

s targeted at the omicron variant remain effective against BA.2.86 and Novavax has stated its updated protein-based COVID-19 vaccine appears effective against "Pirola" as well. As of late August, there had been too few known cases over a relatively short period to accurately evaluate its symptoms and severity, but there were indications that it may be similar to other circulating variants: In three early cases from Denmark and one from Canada, the local authorities reported that symptoms had been similar to those typically seen in COVID-19, none of the small number of globally known cases were reported to have died, and in parts of the U.S. where it had been detected there had not been a disproportionate increase in hospitalizations. Initial lab results from China and Sweden indicate that the variant is neither as contagious nor immune-evasive as some scientists had feared, and is no longer regarded as "the second coming of Omicron". Two studies published in ''

Cell Cell most often refers to: * Cell (biology), the functional basic unit of life * Cellphone, a phone connected to a cellular network * Clandestine cell, a penetration-resistant form of a secret or outlawed organization * Electrochemical cell, a de ...

'' suggest, that while BA.2.86 has reported to have been less contagious, it may lead to more severe disease by entering further into the lower lungs.

Nomenclature

Some news media have used the

colloquial name Colloquialism (also called ''colloquial language'', ''colloquial speech'', ''everyday language'', or ''general parlance'') is the linguistic style used for casual and informal communication. It is the most common form of speech in conversation amo ...

"pirola" to describe the BA.2.86 variant. The name is reported to have been created by a social media user by combining the names of the Greek letters pi and

rho Rho (; uppercase Ρ, lowercase ρ or ; or ) is the seventeenth letter of the Greek alphabet. In the system of Greek numerals it has a value of 100. It is derived from Phoenician alphabet, Phoenician letter resh . Its uppercase form uses the same ...

, which follow the letter omicron in the

Greek alphabet The Greek alphabet has been used to write the Greek language since the late 9th or early 8th century BC. It was derived from the earlier Phoenician alphabet, and is the earliest known alphabetic script to systematically write vowels as wel ...

References

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External links

Outbreak map
with locations of the first 23 positive samples chronologically Variants of SARS-CoV-2 2023 disease outbreaks