The Chinese Center for Disease Control and Prevention released the influenza monitoring weekly report for the 52nd week of 2023 (December 25, 2023- December 31, 2023) on the 4th. The monitoring weekly report shows that the proportion of influenza B has been on the rise recently, with the northern region experiencing a continuous increase for 9 weeks, from 4.2% in the 44th week to 47.3% in the 52nd week; The southern region rose for six consecutive weeks, from 11.6% in the 47th week to 26.4% in the 52nd week; The proportion of influenza B in China has been increasing for six consecutive weeks. What are the symptoms of COVID-19? What are the differences between H1N1 and COVID-19? Will I still get second rate if I get H1N1? Professor Zeng Mei, Deputy Director of the Department of Infectious Diseases at the Affiliated Pediatric Hospital of Fudan University, answered this question. Is influenza B rare and "low-key"? Many people think that influenza B is rare. In Zeng Mei's opinion, this is a misunderstanding. "It is not low-key, and it has always been the epidemic strain of seasonal influenza before the epidemic. In the past flu seasons, influenza has shown an alternating epidemic of influenza A and B viruses." During the COVID-19 period, influenza viruses basically did not break out. In the first half of last year, influenza A H1N1 was dominant, and in the autumn, H3N2 subtype was dominant, Recently, influenza B has become active again and its proportion continues to rise. In fact, influenza B belongs to the "big family" of influenza. The so-called influenza is an acute respiratory infectious disease caused by seasonal influenza viruses. Influenza viruses can be divided into four subtypes: A, B, C, and D. Currently, the H1N1 and H3N2 subtypes of influenza A virus and the Victoria and Yamagata strains of influenza B virus are causing seasonal influenza outbreaks. What is the difference between H1N1 and COVID-19? Zeng Mei told reporters that the symptoms of influenza are very similar. Being infected with the B virus, like the A virus, can cause flu like symptoms (such as fever, chills, chills, coughing, sore throat, runny nose, nasal congestion, accompanied by headache, muscle soreness, and lethargy) 2-4 days after infection; Generally, the sudden onset of the disease is characterized by sudden high fever, with a body temperature of up to 39 ° C-40 ° C. The fever usually lasts for 3-5 days, and symptoms such as runny nose, nasal congestion, and fatigue may persist for several weeks. It was once believed that the symptoms of COVID-19 were milder than those of COVID-19, but experts have clarified that there is no significant difference between the two in terms of clinical symptoms and the proportion of severe cases. There are relatively more middle school aged children in the second class, so the incidence rate of second class may fall after the end of the semester. Two types of viruses do not have cross protection. In clinical practice, there are cases of COVID-19 that have been cured for less than a week and then have been infected with COVID-19. Both are influenza viruses, why do they have no immunity? Zeng Mei explained that there is no cross protection between influenza A virus and influenza B virus infections, so they do not have a protective effect on each other. During the peak season of winter flu, some citizens will self test and purchase medication. Although experts do not advocate this behavior, they believe that it can also be helpful for flu patients in case of inconvenience or emergency, provided that the testing is accurate and medication is precise. At present, the main effective drugs for influenza viruses are oseltamivir and mabaloxavir. Injecting influenza vaccine has protective effects against both H1N1 and H1N1 influenza. Generally speaking, after 2-4 weeks of receiving the influenza vaccine, antibodies with protective levels can be produced, and antibody titers begin to decline from June to August