Shine infections: Vaccination won't save you from Hong Kong flu
The composition of the influenza vaccine recommended by WHO for this epidemic season does not correspond to the Hong Kong variant of the virus that is relevant for Russia, which significantly reduces the degree of protection of people who have been vaccinated, the N.F. Gamaleya Center for Epidemiology and Microbiology told Izvestia. Currently, the regions of Russia are being covered by a wave of Hong Kong flu caused by the A (H3N2) strain, which accounts for more than 80% of all identified cases of respiratory infections. The epidemiological situation is particularly difficult in the Far East, Siberia and the Urals, Rospotrebnadzor reported. Experts predict a peak in the incidence of influenza in January 2026, urging people to get vaccinated. Details can be found in the Izvestia article.
Where the incidence has increased dramatically
Russia has recorded a sharp spike in the incidence of influenza, which is caused by strain A (H3N2) and is known as Hong Kong flu. According to Rospotrebnadzor, it accounts for more than 80% of all identified cases of respiratory infections.
"At the first signs of malaise — fever, headache, cough, runny nose and aches all over the body — it is necessary to call a doctor. You should not visit organized groups and places of mass gathering of people until you recover," the agency's specialists noted.
In Moscow, the incidence also continues to grow, and influenza A(H3N2) viruses predominate among the identified strains, Rospotrebnadzor reported. At the same time, the epidemiological thresholds for the incidence of influenza in the capital have not been exceeded, the Moscow Department of Health emphasized.
According to the Metropolitan Department of Health, rhinovirus dominates in the city, and the Hong Kong flu is present in small numbers. The disease most often "proceeds in a mild form, like a common acute respiratory viral infection," they noted.
The incidence of influenza and acute respiratory viral infections in St. Petersburg increased by 23% in a week - the epidemic thresholds have not yet been exceeded. At the same time, the educational process was temporarily suspended in more than 85 classes of city schools.
In addition, a sharp surge of the influenza virus was recorded in Orenburg, Tver, Smolensk, Khabarovsk and Ulan-Ude. From November 24 to November 30, the epidemic thresholds for the total incidence of influenza and acute respiratory viral infections in these cities were exceeded by 20% or more, calculated at the A.A. Smorodintsev Influenza Research Institute.
Will the flu vaccine help
Rospotrebnadzor specialists have not registered any new atypical pathogens in the country.
"The identified viruses fully correspond to the vaccine strains of the current season, which makes vaccination especially relevant and effective in preventing severe forms of the disease," Rospotrebnadzor reported in its Telegram channel.
The composition of the influenza vaccine recommended by WHO for this epidemic season does not correspond to the Hong Kong variant of the virus that is relevant for Russia, which significantly reduces the degree of protection of people who have been vaccinated, Alexander Ginzburg, director of the N.F. Gamalei National Research Center for Epidemiology and Microbiology, told Izvestia.
— In case of mutations, the effectiveness of the drug should be tested on animals. But according to the available experience of such discrepancies, which occur regularly, the discrepancy, although it does not reduce protection to zero, greatly weakens the effectiveness of vaccination. Therefore, when monitoring mass infectious diseases, you do not need to rely on WHO, but do it on your own," said Alexander Ginzburg.
The scientific center is already working on creating universal vaccines against influenza and coronavirus infection that would protect against all their strains at once, but research is still at an experimental stage. Scientists will need two to three years to complete them, the specialist added.
As reported in the Telegram channel "Virology" by its author, virologist Sergey Olkhovsky, klada K (offshoot. — Ed.) of the Hong Kong flu is close to the vaccine strain of the virus. However, it has managed to accumulate several mutations that greatly alter its antigenicity, which reduces the ability of the vaccine to protect against infection.
"Nevertheless, the vaccine continues to protect against severe cases, hospitalization and death at approximately the same level (effectiveness of 32-39%)," the specialist said.
The new mutations of the Hong Kong strain were also reported by the World Health Organization.
"In June 2025, scientists revealed an increase in the prevalence of the H3N2 strain with seven new mutations, as well as the new H1N1 strain, although so far there are no signs that any of them causes a more severe form of the disease," the WHO said in a statement on its official website.
Mutations of the virus can actually reduce the effectiveness of the vaccine. At the same time, first of all, the barrier that prevents infection weakens, immunologist Mikhail Bolkov told Izvestia.
— In this case, the vaccine protects less, but the protective effect remains, since the antigenic surface of the virus has not changed completely, but only partially. At the same time, the vaccine is polyvalent. There are influenza A, H1N1, H3N2, and influenza B, so it will continue to operate. Mutations can reduce all aspects of protection. Technically, the infection barrier may weaken, but special studies are needed to find out. But there are none, as we are monitoring the situation in real time," Mikhail Bolkov said.
By the beginning of December 2025, more than 52% of Russians — more than 78 million people - had been vaccinated against influenza, Rospotrebnadzor reported.
How to protect yourself from the Hong Kong flu
Those infected with the Hong Kong flu have a sharp onset of the disease, with an acute increase in temperature to 39 degrees or more, Andrei Pozdnyakov, Candidate of Medical Sciences, infectious diseases specialist at the Invitro clinic, reminded Izvestia.
— The disease is accompanied by severe intoxication, headache, patients complain of pain in muscles and joints. Then a cough appears, and by the end of the second day it becomes painful. That is, this is the whole classic flu picture. This is influenza A (H3N2), it's called Hong Kong flu in the old—fashioned way," the specialist noted.
The doctor stressed that patients who have not been vaccinated are most often infected with the flu.
— If you look at the number of people vaccinated against the flu, the numbers are depressing, so the flu will spread further. This infection is quite volatile and highly contagious. Moreover, the warm weather without frost contributes to this," he believes.
Andrey Pozdnyakov recommends that rooms be ventilated more often, that masks be worn in crowded places, and that it be better not to visit crowded places unnecessarily.
— We should not forget about the diagnosis of influenza. There are rapid tests and a fairly fast PCR diagnosis. There are drugs that destroy influenza viruses, but they are effective in the first two days after the onset of the disease. Such therapy prevents the development of severe forms and complications," the doctor said.
Vladislav Zhemchugov, MD, an immunologist, called the A (H3N2) strain that causes the Hong Kong flu "common seasonal" and one of the most common in Russia.
— This is a common home strain, it is fixed every year. There are more dangerous types of flu, for example, "Spanish flu". And there is nothing special about the Hong Kong flu, its antigen is found in all vaccines. There are the most people vaccinated against this strain of flu," he told Izvestia.
According to the doctor, the flu virus can cause serious complications, such as influenza meningitis and bacterial pneumonia, if treatment is not started in the first 3-4 days.
Переведено сервисом «Яндекс Переводчик»
