Is it true that the new COVID strain PJ.2.1 is very dangerous and is being hidden in Russia and Kazakhstan?

True. It is a descendant of Omicron (lineage MC.10.1) with more than 25 changes in the spike protein, which the virus uses to enter cells. The first sample was found in Ontario, Canada, in May 2026. The variant was later found in the US, Spain and other countries.^[1][2][19]

No evidence. The WHO says there is no published clinical data showing more severe illness than with other recent variants. Rospotrebnadzor (Russia's consumer health watchdog) sees no rise in pneumonia, respiratory failure or hospitalizations. Kazakhstan's Ministry of Health also sees no signs of more severe disease.^[9][8][20]

Not confirmed so far. Two non-peer-reviewed lab studies showed that antibodies of people who had COVID or were vaccinated handle PJ.2.1 about as well as other variants. Its distinctive feature is different: it binds to cells more tightly, so it may spread more easily.^[1][2]

Partly true. In Ontario its share of tested samples rose from 3.1% to 13.0% (from late July to September 19). That is 30 samples out of 231, so the sample is small. The WHO calls its global share insignificant, but warns that the risk of it being brought in by travel is growing.^[3][9][10]

Not confirmed. Rospotrebnadzor and the WHO report no registered cases in Russia. Kazakhstan's Ministry of Health did not find PJ.2.1 in the samples it checked. Scientists allow that some cases may have gone unnoticed.^{[10][16][20][17]}

No evidence. The WHO explains the lack of detected cases by the variant's small share and by relatively little genome sequencing of the virus in Russia (decoding its genetic code). In other words, it may simply be going unnoticed. Media and agencies discuss the topic openly.^[10][17]

This is what some doctors say. The publications cite no studies or data from test makers.^[18][17]

In May 2026 the first PJ.2.1 sample is found in Ontario, Canada. The exact day is not given in open scientific data.^[2]

First lab study (not peer-reviewed): the variant binds strongly to cells but does not escape antibodies noticeably more than others.^[2]

Ontario report: PJ.2.1 became the most common variant, at 13% of 231 tested samples.^[3]

Second study (Germany, not peer-reviewed): the variant is spreading in the US, Canada and Spain, more often among people over 60. No strong immune escape.^[1]

Article about an "ultramutant": the strain may arrive in Russia or may already be here unnoticed. Doctors say rapid tests may miss it.^[17][18]

The agency: no cases in Russia, and no signs of more severe illness either.^[8][16]

The WHO requests data to update vaccine composition in December. PJ.2.1 is mentioned among "potentially new" variants.^[6]

The risk of the variant being brought in is growing because of travel, but there is no clinical data on more severe illness.^[9][15]

Academician Gennady Onishchenko: there will be no pandemic, and there is no data on greater aggressiveness.^[14]

No confirmed cases in Russia. The variant's share is insignificant, and the low volume of sample testing makes it hard to find.^[10]

Kazakhstan's Ministry of Health: PJ.2.1 was not found in the samples checked, and there is no data on more severe disease.^[20]

In December the WHO will review PJ.2.1, ST.1 and SW.2.1 as part of updating vaccine composition. PJ.2.1's growing share is not accompanied by an overall rise in cases.^[11][12]

Virologist Malinnikova: PJ.2.1 "supposedly" causes a worse sore throat and longer fatigue. She cited no data.^[13]

No cases in Russia, no signs of more severe illness. This is the agency's official position.^[8][16]

The risk of the variant being brought in is growing, but there is no data on severe illness. No confirmed cases in Russia, and few samples are tested there.^[9][10]

In December WHO experts will review PJ.2.1 along with other variants when updating vaccine composition. It is not causing an overall rise in cases.^[11][12]

The variant was not found in the samples checked, and there is no data on more severe disease.^[20]

As of October 30, PJ.2.1 is not on any list of variants under special monitoring.^[4]

Introduced the word "ultramutant" and the idea that the strain may already be in Russia unnoticed. It does not attribute severe symptoms to it.^[17]

"More contagious, but unlikely more dangerous": a calm explainer.^[19]

No separate fact-checks on PJ.2.1 found.

Science thread: new samples from Spain, the variant seems to be spreading worldwide, but it is too early to say whether it will become dominant.^[23]

An independent analyst writes that in Ontario PJ.2.1 shares first place with variant XFG, at about 35%. This is not official statistics.^[24]

結果： There was no more severe illness. Its descendant JN.1 later became the dominant variant in winter 2023–24, but without particular severity.^[22]

結果： Kazakhstan's Ministry of Health: the variant has long been in the country, the situation is stable, and there are 3.8 times fewer cases than a year ago.^[21]