Chinanews.com, Beijing, December 20 (Shao Meng) The new coronavirus variant JN.1 is accelerating its spread around the world, and local cases have also appeared in the mainland. The National Bureau of Disease Control and Prevention issued a document on the 15th, saying that as of December 10, a total of 7 cases of the JN.1 variant have been monitored in local cases in the mainland. The news sent JN.1 to the spotlight on social media.
How is the JN.1 variant different from the previous coronavirus, how fast and pathogenic is it, what is the impact on the peak of respiratory infections that the country is experiencing, and will it trigger a new epidemic on the mainland?
In response to the above questions, Chinanews interviewed Lu Hongzhou, director of the National Clinical Research Center for Infectious Diseases and president of the Third People's Hospital of Shenzhen, and Jiang Qingwu, an epidemiologist and professor at the School of Public Health of Fudan University.
The JN.1 variant has been circulating in many countries
The possibility of becoming the dominant epidemic strain in the mainland cannot be ruled out
Lu Hongzhou told Chinanews that the JN.1 mutant strain is a subclade of the new coronavirus Omicron variant BA.2.86, and compared with BA.2.86, the receptor binding region (RBD region) of the JN.1 variant has an additional L455S mutation. Recent studies have found that the L455S mutation of the JN.1 mutant strain further enhances its immune evasion ability.
The results of global monitoring show that in November, the growth rate of BA.2.86, especially the subclade of JN.1, has accelerated significantly in the global proportion, and has become one of the dominant epidemic strains in some countries. As of December 10, the JN.1 variant has been detected in at least 40 countries around the world. On December 19, the World Health Organization singled out the JN.1 variant as a "variant of concern". The JN.1 variant poses a low additional risk to global public health at this time, but could increase the burden on public health systems in many countries to deal with respiratory infections as winter approaches in the northern hemisphere, WHO said.
Chang Zhaorui, a researcher at the Infectious Disease Management Department of the Chinese Center for Disease Control and Prevention, said at a press conference of the National Health Commission on December 17 that the monitoring results of the new coronavirus variant in the mainland show that the BA.2.86 variant currently accounts for a very low proportion of the reported sequence in the mainland, but the proportion of imported cases has increased rapidly since November, and the growth trend is gradually converging with the world.
Trends of change. Source: China Center for Disease Control and Prevention
The popular science article released by the National Bureau of Disease Control and Prevention also pointed out that although the current prevalence level of the JN.1 variant in the mainland is extremely low, it is not ruled out that the JN.1 variant may become the dominant epidemic strain in China due to the subsequent impact of international epidemic strains and imported cases.
Experts say there is still a need to be vigilant against a rebound of the new crown this winter
Does it worsen the wave of respiratory infections?
At present, the mainland is in the season of high incidence of respiratory infections, what impact will the introduction of the JN.1 variant have on the peak of respiratory infections that China is experiencing, and will it trigger a new round of epidemics?
In Jiang Qingwu's view, the prevention and control of influenza has been normalized, and the pathogenic mutation of influenza viruses cannot be stopped, and the incidence of influenza in this autumn and winter is more than in the previous three years. At present, the influenza infection situation in mainland China has shown signs of easing, and the number of outpatient and emergency respiratory disease diagnosis and treatment and the number of hospitalizations in hospitals are declining. The Weekly Report on Influenza Surveillance for Week 49 (December 4-10) also showed a downward trend in the positive rate of influenza virus tests in individual provinces during the week.
"My concern is that this wave is mainly the flu, and the COVID infection is at a low level of circulation. However, according to the previous transmission pattern and epidemic characteristics of the new coronavirus, in late December and January, we need to be highly vigilant that the new coronavirus will affect us again. At present, there are countries where the spread of the new crown is far more active than ours. Jiang Qingwu said that it is recommended to actively prepare for the prevention and control of respiratory infectious diseases.
Data map. Photo by Zhang Yuhui
Lu Hongzhou said that although the immune evasion ability of JN.1 has increased, there is currently no evidence that JN.1 has increased pathogenicity. In addition, since December last year, the new coronavirus and other respiratory pathogens have been co-circulating in the mainland, and mainland residents have generally experienced two or even three infections. It has been shown that such an experience of infection can lead to a strong and broad-spectrum of neutralizing antibodies against different submutant strains of Omicron in infected individuals.
"The future epidemic of JN.1 in the mainland may cause a small spike in infection, which will increase the medical burden of hospitals to a certain extent, but our existing experience and medical resources are sufficient to cope with this situation, so theoretically JN.1 will not have much impact on the peak of respiratory disease infections that the mainland is experiencing. Lu Hongzhou speculated.
The risk of severe clinical infection is low
COVID-19 vaccines containing XBB.1.5 are still effective
According to the National Bureau of Disease Control and Prevention, studies have shown that there is no significant difference between the JN.1 and XBB variants in terms of transmission. The World Health Organization (WHO) has assessed the risk of severe clinical infection of the BA.2.86 variant, including JN.1, as low. Mainland surveillance data shows that the JN.1 variant infection is mild or asymptomatic.
In addition, the World Health Organization (WHO) reported that XBB.1.5-containing COVID-19 vaccines are still effective against the JN.1 variant.
Lu Hongzhou introduced that at present, the mainland has approved a total of 5 new crown vaccines containing XBB mutant strain components, including recombinant protein vaccines, mRNA vaccines and recombinant adenovirus vector vaccines.
He said that although recent studies have found that the L455S mutation of the JN.1 mutant strain further enhances its immune evasion ability and has a certain escape ability to the humoral immunity induced by XBB.1.5 breakthrough infection, the existing data also show that vaccination can significantly increase the speed and intensity of antibody production and provide better protection for the body, so vaccination is still necessary.
An elderly man gets vaccinated against the coronavirus. Photo by Zhou Lishuo
Jiang Qingwu also pointed out that effective vaccination is an effective measure to control the spread of infectious diseases and protect the population, and influenza vaccination should be actively promoted, especially for children and the elderly. Regions and industries with conditions can promote free influenza vaccination.
In addition, some effective crowd control measures in the past should be actively advocated, such as washing hands after returning from going out, advocating the wearing of masks in indoor public places and transportation during the epidemic season, strengthening prevention, control and monitoring by medical and public health departments, and health supervision departments to do a good job in the management of fever clinics, and analyzing and publishing information on the incidence of fever in a timely manner.
"Although the pathogenicity of the new crown is decreasing, it is still necessary to attach great importance to the protection of the elderly and recommend the most effective vaccines to the elderly population. The season for the spread of respiratory infectious diseases has arrived, and the medical and public health departments need to make technical and material preparations. Jiang Qingwu said. (ENDS)
(China News Network)