A new SARS-CoV-2 variant, PJ.2.1, is drawing attention from health agencies around the world after being detected in at least eight countries, with researchers describing it as a “novel saltation variant” that carries an unusually large number of mutations in its spike protein.
The lineage was first detected in Ontario, Canada, on 2 May 2026, and has since been reported in the United States, Singapore, Australia, New Zealand, Israel, France and Spain. A study published in the Journal of Infection in October 2026 documents its spread, its characteristics and how well antibodies generated by variant-adapted booster vaccines can neutralise it.
PJ.2.1 originated from MC.10.1.7, a descendant of the JN.1 lineage that circulated until May 2025. The researchers described it as a saltation variant, a term used for a virus that emerges with a sudden jump in mutations rather than through gradual change, and noted that it carries several changes in the spike protein compared with its parent lineage.
In the United States, the first case was reported in New York City on 30 June, followed by detections in California, Florida, Arizona, New Jersey, Virginia, North Carolina, Missouri, Oklahoma and Colorado. Based on wastewater surveillance, the researchers described PJ.2.1 as the “fastest-growing variant in the USA” at the time of the study.
Genomic surveillance in Ontario showed the variant accounting for 25.2 per cent of sequenced SARS-CoV-2 samples between 20 September and 17 October, up from 16.9 per cent in the previous four-week period. Hong Kong’s Centre for Health Protection also detected the variant in its surveillance data, according to an update on 5 November.
Laboratory work in the study found that PJ.2.1 has an enhanced binding affinity for ACE2, the human cellular receptor the virus uses to enter cells, and that it was more frequently detected in older age groups, particularly people aged 70 and over. The experiments were conducted in laboratory models, and the results cannot yet confirm how efficiently the variant spreads between people in the real world.
There is currently no convincing evidence that PJ.2.1 causes more severe illness, higher hospitalisation rates or more deaths than other circulating Covid-19 variants, according to the reports. The World Health Organisation said it is closely monitoring the emerging variant amid growing concern over its spread, although its variant list updated on 27 July 2026 did not include PJ.2.1 among the variants under monitoring.
The variant’s spread has prompted questions about whether it could fuel another wave of infections, but health experts have stressed that Covid-19 continues to circulate globally and remains a cause of considerable illness and death, and that the emergence of new lineages is expected. The symptoms reported are similar to those of other Omicron-lineage infections, including fever, cough, fatigue and sore throat.
In India, there is no confirmed evidence of widespread transmission of PJ.2.1, according to reports citing available surveillance information. The country’s genomic surveillance network, INSACOG, monitors changes in the coronavirus and identifies emerging variants through genome sequencing.
For now, the advice from health agencies remains unchanged: vaccination, particularly with variant-adapted boosters, remains the best protection against severe disease, and surveillance networks will continue to track PJ.2.1 as it spreads. Whether it becomes dominant, or fades like many variants before it, will become clear over the coming weeks.
