Local confirmed cases reappeared in many places across the country. The current round of epidemic, which is connected by "tour groups", has affected 11 provinces, autonomous regions and cities such as Shaanxi, Ningxia, Inner Mongolia, Beijing, Gansu and Hunan. At 15:00 on October 24, the joint prevention and control mechanism of the State Council held a press conference. The relevant person in charge of the disease control bureau of the National Health Commission introduced that the epidemic had a wide range and strong infectivity. As of 24:00 on October 23, 133 infected persons had been reported in total. In order to further strengthen the immune barrier, Changping District of Beijing promoted the new crown vaccine and strengthened needle vaccination. The picture shows citizens inoculated at the temporary vaccination point of Yong'an activity center, Chengbei street, Changping District on October 23. Photographed by Xinhua News Agency reporter Chen Zhonghao With the advent of autumn and winter, COVID-19 has risen again. According to incomplete statistics, as of October 21, 17 provinces (autonomous regions and municipalities directly under the central government) including Beijing, Guangdong, Zhejiang and Hubei have successively started new crown vaccination and strengthened needle vaccination. What is the principle of reinforcing needle? Can it effectively fight the mutant strain? Which groups recommend vaccination booster? The reporter conducted an interview on this. The "staggered peak tour of the elderly group" triggered the spread of the local epidemic related to the source of overseas input, and the strengthening of vaccination helps to build a strong immune barrier On October 17, Xi'an, Shaanxi reported that a couple of tourists from other provinces were nucleic acid positive and were diagnosed as confirmed cases. On October 18, Xi'an informed tourists that the nucleic acid test results of the seven tour groups where Yan's husband and wife were located were all positive, including 6 confirmed cases and 1 asymptomatic infected person. On the same day, Yinchuan, Ningxia reported a confirmed case and traveled with the above seven people. At present, the source of the epidemic is still in the process of tracing the source of flow regulation, and the transmission chain is relatively clear. Of the 133 cases of infection reported, 106 cases are related to the transmission chain of tour groups, involving 13 tour groups or self driving tours. Domestic epidemic sporadic distribution, while foreign COVID-19 has rebounded significantly. More than 330000 people were diagnosed in the UK in the past week, up 15% compared with the previous week, and the death toll rose 12%. The cumulative death toll increased to 139461. The Robert Koch Institute, a German disease control agency, reported on the 23rd that 15145 newly confirmed cases in Germany in the past 24 hours, 4196 more than a week ago. The 7-day infection rate in Germany reached 100, the highest since mid May. A week ago, the figure was 70.8. Foreign experts believe that the rebound of the epidemic situation is related to seasonal factors, low vaccination rate, possible decline of vaccine efficacy over time, relaxation of epidemic prevention and control measures, etc. As of October 23rd, 31 provinces (autonomous regions and municipalities directly under the central government) and the Xinjiang production and Construction Corps reported a total of 2 billion 244 million 727 thousand doses of COVID-19 vaccine, according to the data released by the national health and Health Committee. It is worth noting that, in the context of "receiving all that should be received", many confirmed cases are still "successful" after they have been vaccinated with two doses of new crown vaccine. What is the medical principle of strengthening immunity? Can it stop the "fish out of the net" that the first two vaccines can't stop? "Strengthening needles" means that the vaccine is repeated after the completion of the new crown vaccination, and the body is immune to COVID-19. The professor Xu Ke, Professor of VIP at Wuhan University, told reporters that the principle of the new crown vaccine is that after neutralization, the neutralization antibody will disappear after a period of time. But the body will produce corresponding memory B cells. After another dose of vaccine, it will induce a large number of memory B cells to proliferate and produce antibodies, so that the body can maintain high immunity again. Xu Ke provided a set of data to the reporter: the clinical data of intensive needle research conducted by Kexing company showed that the neutralizing antibody titer of 540 subjects decreased to gmt4.1-6.7 (GMT refers to antibody titer. The larger the value, the stronger the immunogenicity and the higher the protective power of vaccine components) after receiving two doses of Kexing inactivated vaccine for 6-8 months. However, after the third injection, the antibody level increased rapidly to gmt137.9-143.1. In addition, according to the data released by kangxinuo company, the neutralizing antibody level can be increased up to 300 times when two doses of inactivated vaccine and one dose of inhaled adenovirus vector vaccine are used as reinforcing needles, "it can be seen that strengthening immunization can improve the neutralization ability of mutant virus." "We can see that some people's immunity is declining and the protection effect is weakening for a period of time after vaccination. To solve this problem, the vaccine R & D special class organized relevant experts to demonstrate, and relevant enterprises also reported the research results of strengthening post immunization clinical trials." Wang Huaqing, chief expert of immunization planning of China CDC, said that the research results show that, By strengthening immunization, no serious adverse reactions occurred, and the rapid growth or rebound of neutralizing antibodies was also seen. Many places across the country have opened vaccines to strengthen immunization, giving priority to key populations, and the antibody level after vaccination can reach 10-30 times of the original On the morning of October 21, the reporter came to Beijing Guang'an gymnasium, which is the vaccination point of Guanganmen street and Niujie street in Xicheng District. The vaccination entrances of the first, second and third injections were clearly distinguished. Citizens lined up to show the travel code, health code, temperature measurement, fill in the new crown vaccination informed consent form, vaccination and observation... Although the flow of people on site was large, it was in good order. "Like the previous two injections, I don't feel much after the injection, but my arm is a little sour." brother Zhao, an environmental sanitation worker in Xicheng District who has just received the booster injection, told reporters that he came for the injection at the first time after receiving the notice from his unit. "When the weather is cold, outdoor workers like us are vulnerable to cold and their immunity is reduced. Recently, there have been confirmed cases in Beijing. It will be more reassuring to have a third injection." On site staff told reporters that at this stage, Beijing mainly organizes vaccination through various industries and units for key groups with high risk of infection and disease transmission. Ordinary people who meet the vaccination conditions and have vaccination needs can strengthen immunization through registration and appointment in their communities and vaccination sites organized by their units. "Each street may have different vaccination arrangements due to different specific conditions. It's best to ask the community first." Among the key groups that give priority to vaccination in Beijing, in addition to the front-line staff who maintain the basic operation of society such as border ports and medical, fire and public security, the security personnel and participants of the Winter Olympic Games, winter Paralympic Games and other major activities have also been included in the scope of giving priority to immunization. Since October, Zhejiang, Hubei, Guangxi, Fujian, Heilongjiang and other places have successively started the vaccination of booster shots, and different places have different regulations on the minimum age limit of vaccinated people and whether to give priority to key people. In terms of vaccination age, most regions stipulate that the vaccination objects of this booster vaccination are mainly people over the age of 18 who have completed vaccination for 6 months. Some regions such as Wuhu, Anhui and Xiamen, Fujian have opened the booster vaccination of inactivated vaccine over the age of 12. In terms of population restrictions, Hubei, Guangxi, Fujian and other places have clearly given priority to vaccination of key populations, while some areas such as Jinan, Shandong, Hefei, Anhui and Suihua, Heilongjiang have not clearly defined the restrictions on key populations. After vaccination, how long can the antibody level be improved? "The antibody level began to rise after 3 days of vaccination, and rose to a higher level after 7 days. By 14 days, the antibody level was about 10-30 times the original level, and it could still be maintained at a relatively high level in another 6 months." Lan Wenzhan, deputy director of the disease prevention and Control Department of the health and Health Commission of Guangxi Zhuang Autonomous Region, told reporters that after vaccination, a few people will have general reactions, such as fever, headache General pain and other symptoms do not need to go to the hospital, but if the symptoms are serious and last for a long time, it is recommended to go to the hospital for diagnosis and treatment in time. It should be noted that people with allergic reactions during the first and second injections are not recommended to be inoculated with booster injections. With the advent of autumn and winter, there is a risk of superinfection of respiratory diseases such as COVID-19 and influenza. LAN Wen said that the current research on the immunogenicity and safety of influenza vaccine and COVID-19 vaccine is still ongoing. Referring to our COVID-19 vaccination technology guide (First Edition), it is recommended that the interval between influenza vaccine and COVID-19 vaccine should exceed 14 days. However, when vaccination against rabies, tetanus vaccine and immunoglobulin is needed for reasons such as animal injury and trauma, the vaccination interval with COVID-19 vaccine is not considered. China's vaccine research and development and production have been breakthroughs. COVID-19 universal spectrum vaccine is being developed, and it is expected that more effective vaccines will be available. Delta's new crown variant is raging in more than 100 countries around the world. People who have been vaccinated will still be infected with delta mutant strains. This "breakthrough infection" phenomenon makes people question whether the vaccine can widely prevent new mutant strains. "The protective effect of any vaccine on infectious diseases cannot be 100%. Even if the booster injection is given, the protective effect cannot be 100%. The purpose of vaccination is to consolidate and strengthen the immune effect of the vaccinated vaccine in the early stage." Lan Wenzhan told reporters that in the previous epidemic in Guangzhou caused by delta mutant strain, relevant studies show that, The protective effect of novel coronavirus pneumonia reached 70% after two inoculation, and the protective effect on severe cases reached 100%. This indicates that COVID-19 vaccine is effective in preventing infection and severe infection of the delta strain. Be the most changeful COVID-19, what is the latest development of vaccine research in China? At present, there are three different technical routes for vaccines produced and listed in China, namely inactivated vaccine, recombinant subunit vaccine and adenovirus vector vaccine. The manufacturers include Sinopharm China biology, Kexing, kangxinuo biology, Zhifei biology and other enterprises. "For viruses with rapid mutation like Xinguan, the vaccine needs to be further updated according to the research results. The best choice is to develop a universal vaccine, which can produce immune protection against different mutant strains." Xu Ke introduced that at present, the research concept and design of universal vaccine have been put forward, but it still needs time for a large number of experimental verification. According to reporter's understanding, the National Key Laboratory of Virology at Wuhan University is developing COVID-19's broad-spectrum universal vaccine, which can neutralize various mutant viruses. "But all vaccine induced antibodies have a maintenance cycle. The length of the maintenance cycle depends on the type of virus, vaccine type and adjuvant effect." according to the current study, Xu Ke said the antibody against the new crown vaccine can last for about 6 months. With the deepening of COVID-19's pathogenic mechanism and vaccine research, a more durable vaccine will emerge. Liu Jingzhen, chairman of China Pharmaceutical Group Co., Ltd. pointed out that the development of China's biotech vaccine against COVID-19 beta strain and delta strain inactivated vaccine has been upgraded. Meanwhile, the development of mRNA vaccine has broken through the key nodes, and the one or two phase of the new clinical research on recombinant vaccine has been completed. For the second-generation broad-spectrum recombinant vaccine of all found variants, Sinopharm has also reached extensive cooperation with countries in the Middle East, South America, Europe, Africa and other regions, cooperated with local institutions to carry out phase III clinical trials and accelerate vaccine research and development. In terms of vaccine production, Liu Jingzhen said, "Sinopharm group has six production bases in Beijing, Shanghai, Lanzhou, Chengdu, Changchun and Wuhan. So far, it has produced and supplied nearly 2.5 billion doses of vaccine, and the annual production capacity has exceeded 8 billion doses. It should be able to meet the needs of the third dose of booster vaccination in China and the international market