Hong Kong wheeze: flu incidence in Russia increased by 35 in two weeks%
The incidence rate of acute respiratory viral infections and influenza in Russia has been growing for five weeks in a row, according to data from the Smorodintsev Influenza Research Institute. The situation is particularly acute in Voronezh, Smolensk, Pskov, Yekaterinburg and 17 other cities. Rospotrebnadzor claims that the situation with the spread of Hong Kong flu in Russia is under control, but in Europe the incidence is growing rapidly. About the regions in which the number of cases of Hong Kong flu has increased and how dangerous it is, see the Izvestia article.
Where the incidence is exceeded
The incidence of influenza and acute respiratory diseases in the 50th week of 2025 (from December 8 to December 14, 2025) was 24.9% higher than the weekly epidemic threshold. Now its level is 106.2 per 10,000 people, whereas a week earlier the figure was 94.6 per 10,000, and before that it was 78.6. Growth has been recorded for the fifth week in a row.
The epidemic threshold of morbidity has been exceeded by 20% in 21 cities. Among them are Voronezh, Smolensk, Pskov, Yekaterinburg, Tver, Tula, Khabarovsk, Cheboksary and Chita. Experts examined the materials of flu patients in 45 cities, in 43 the influenza A (H3N2) virus is circulating, including the Hong Kong variant of the virus, which has been spreading especially actively since the summer of 2025. In the previous week, the surveillance threshold was exceeded only in 13 cities.
According to the Influenza Research Institute, the incidence in mid-December 2025 is higher than in the same period last year. So, in 2024, the epidemic thresholds for the incidence of influenza and acute respiratory viral infections in the entire population were exceeded by more than 20% in only seven cities: Bryansk, Vladivostok, Kirov, Murmansk, Orenburg, Ulan-Ude and Chita.
Rospotrebnadzor said that the seasonal increase in the incidence of acute respiratory viral infections and influenza continues in Russia, but over the past week the growth rate has slowed by about a third. They noted that the proportion of people hospitalized with influenza and acute respiratory viral infections remains low at 1.8%. At the same time, in early December, the department noted that the Hong Kong flu virus dominates, accounting for about 80% of infections.
In Russia, the flu vaccination campaign started on September 4, 2025, and with the current vaccination coverage of 54.5% of the population, the incidence is estimated to be moderate — about 1-1.3 million cases of acute respiratory viral infections and influenza per week. To date, the number of vaccinated cases is 0.004% of the total number of people vaccinated against influenza.
What is the incidence in Europe
In Europe, the flu season started four weeks earlier, Rospotrebnadzor said. It is also the Hong Kong type of flu that dominates there. The reason is the low level of vaccination and, as a result, high morbidity.
— The flu comes in the winter every year, but this year everything is a little different. The situation shows that even a small genetic mutation of the disease can put enormous pressure on our health services," said Hans Kluge, Director of the WHO Regional Office for Europe.
According to WHO forecasts, the flu season in Europe will peak by the end of December or the beginning of January. The organization noted that the situation is serious, but it does not reach the level of a global emergency, as during the COVID-19 pandemic.
According to the WHO, about 90% of confirmed cases of influenza in Europe occur in the Hong Kong variant. So, in France, medical services note a significantly strong activity of such a strain among different age categories, in Spain the number of cases of infection has already exceeded last year's figures, and in Germany the flu season began two to three weeks earlier than usual.
At the beginning of the year, WHO usually publishes recommendations on which subspecies of the influenza virus should be included in preventive vaccines. Sergey Netesov, head of the Laboratory of Bionanotechnology, Microbiology and Virology at the NSU PHEN, recalled that the Hong Kong variant of the influenza virus, the H3N2 subtype of the influenza A virus, spread only in the summer.
Thus, the H3N2 variant first appeared in 1968 and has been circulating among humans ever since, but it has been evolving, changing its antigenic properties and thus eluding the immune response to its previous variants. There wasn't much of it in the 2024-2025 season, but this spring its evolution branched out. As a result, the vaccine was updated for one branch, and the variants of the virus began to rapidly change along the other branch.
— When the virus evolves, it changes its antigenic structure and escapes the action of vaccines, — said the expert.
He added that a person vaccinated with the vaccines that are in circulation now may get sick, but the disease will be much easier than in an unvaccinated person. People from risk groups should be especially careful: over 65 years of age, with serious chronic diseases of the heart, lungs, kidneys and liver, with transplanted organs, with diabetes and HIV.
Is Russia facing a flu epidemic
Mutations have made the variant of the flu virus that is now spreading in Russia more contagious. And the disease proceeds with more intense symptoms, Andrey Prodeus, chief pediatric allergist and immunologist at the Ministry of Health of the Moscow Region, told Izvestia.
— The current flu variant is intense, with a small number of catarrhal phenomena, but with a high temperature reaction. This makes it more dangerous for children and the elderly, especially hypertensive patients and patients with heart and vascular diseases. In principle, high fever is harmful to them, so it must be controlled," said Andrey Prodeus.
According to the specialist, the influenza A variant is currently circulating in the country, and by February or March it should change to B. To be ready for this, it is necessary to increase the number of vaccinated people in the population, the specialist emphasized.
According to Mikhail Bolkov, a researcher at the Russian National Research Medical University, the current flu strain has no special properties, and its mutations are a natural process called genetic drift.
— This happens every year. This is a completely normal variability of the influenza virus. There is nothing supernatural about it to distinguish it from other variants and its symptoms are "classic," Mikhail Bolkov noted.
Sergey Voznesensky, associate Professor of the Department of Infectious Diseases with courses in Epidemiology and Phthisiology at RUDN University, agrees with the fact that the manifestations of influenza this year fully fit into the usual picture.
— The flu is a disease that, with mild severity, causes a temperature of 38.5 degrees. Therefore, temperatures of 40 and above are quite common. Intoxication or fever with the flu lasts an average of three to four days. Therefore, five days is normal. At the same time, intoxication with the influenza virus is more severe than with all other infections," said Sergey Voznesensky.
In his opinion, the incidence rate will begin to decrease only in two weeks.
Переведено сервисом «Яндекс Переводчик»
