New COVID variant PJ.2.1 spreads from Canada to the US, Europe and Asia. WHO sees no higher severity so far

A new COVID-19 variant called PJ.2.1 is turning up in more countries, and the World Health Organization says it is watching closely. So far, the WHO says current laboratory and clinical data show no clear difference in severity compared with earlier variants.

Here is the timeline. The first documented sample was collected in Ontario, Canada, on May 2, 2026. Detections followed in Alberta, British Columbia and New Brunswick.

The first US detection came in a patient in New York City on June 30. Cases have since been reported in California, Arizona, New Jersey, Virginia, North Carolina, Missouri, Oklahoma, Colorado and Florida.

The variant has also been found in Singapore, Australia, New Zealand, Israel, France and Spain. In Spain, researchers identified local transmission chains in Catalunya, the Basque Country and the Community of Madrid.

What makes it unusual

PJ.2.1 is classed as a saltation variant. Instead of picking up mutations a few at a time, it appeared with a large batch of changes at once. Researchers say such variants are thought to evolve during persistent infections before re-entering the wider population.

A study in the Journal of Infection, led by Markus Hoffmann and colleagues, traces PJ.2.1 to MC.10.1.7, a descendant of the JN.1 lineage that circulated until May 2025. RTTNews counts more than 25 mutations in its spike protein, the part of the virus that latches onto human cells.

Heavy spike mutation normally raises the concern that a variant will slip past immunity. The early lab results point somewhere else. The study found PJ.2.1's spike binds more strongly to the ACE2 receptor, with greater cell-entry efficiency in certain cell lines, including cells with low ACE2 levels. It did not find substantial escape from antibodies produced after updated, variant-adapted vaccination. Antibodies from people who received an LP.8.1-adapted vaccine were only 1.8 times less effective against PJ.2.1 than against LP.8.1.

"A variant spreading faster does not necessarily mean it causes more severe disease," Dr Amit Saraf, director of internal medicine at Jupiter Hospital in Thane, told The Indian Express.

How fast it is growing

Growth has been measurable. Researchers said wastewater surveillance showed PJ.2.1 was the fastest-growing variant in the US at the time of their analysis.

Public Health Ontario's genomic surveillance shows the variant made up 25.2% of sequenced SARS-CoV-2 samples between September 20 and October 17, up from 16.9% in the preceding four-week period. It was the most frequently identified lineage in that reporting period.

Those are shares of sequenced samples, not counts of infections, and they cover one province.

What is not known

The lab findings come with limits. Mathrubhumi English notes that laboratory binding results alone cannot establish how readily the variant spreads between people in everyday settings.

There is also no clinical evidence yet on hospitalization rates or deaths. Several explainers put it the same way: insufficient evidence to say PJ.2.1 causes more dangerous illness, and equally no proof its severity matches earlier strains.

The WHO has also said symptoms resemble those of a common cold or influenza, so the variant cannot be identified by how someone feels. A routine test shows only whether a person has COVID-19. Confirming PJ.2.1 requires genomic sequencing.

Researchers also noted the variant was detected more often among people aged 70 and above, though that does not establish that it targets older people or causes severe disease in them.

Who is still at risk

Most cases are expected to be mild, according to doctors quoted in Indian coverage. The elderly and immunocompromised remain vulnerable to serious complications, as with every COVID variant to date.

In India, reports show no confirmed widespread transmission and nothing suggesting restrictions are needed. The standard advice from health experts is to get tested when symptomatic, stay current on vaccination and avoid close contact with others while sick.

What to watch

The WHO has said it is monitoring PJ.2.1 because of its growing geographic spread. The next data that matter are hospital admissions and death counts in places where the variant is growing, such as Ontario, and a follow-up on whether the early antibody results hold up against more recent vaccine-induced and infection-induced immunity. Until then, it is unclear whether a variant that spreads this efficiently will remain mild.