On the vaccination questions, the CDC experts give authoritative answers

outbreak of new crown pneumonia is still raging around the world, vaccines have become an important means to fight the new crown epidemic around the world. As of 2400 hours on February 3, the country has reported 3.1236 million doses of the new coronavirus vaccine in key population groups. On vaccination, safety, how to achieve mass immunization and other issues, China Center for Disease Control and Prevention researchers, the World Health Organization vaccine research and development
will be consultant Yan Yiming accepted the China News Agency", "China Focus face-to-face" interview, to make authoritative answers.My country belongs to fast. It should be said that our country's new crown (pneumonia) vaccine research belongs to the world's first legion, is the first country to start clinical trials, but also the first to enter the phase III clinical country.
We are the first country to approve vaccines for emergency use in July 2020 under the coordination of the vaccine research and development team, the
Joint Prevention and Control Coordination Mechanism vaccine team and the National Drug Administration. China's higher-risk groups, prevention and control of the front-line team, customs border and some important jobs, such as dock staff, related to imported goods, students working abroad, from then on began the emergency vaccination of vaccines.
should say that the country's work arrangements are scientific and sound. Because unlike many countries in the world, there is not much risk of disease in our country. Most of the time last summer and fall, there were single-digit new home-grown cases per day, and very few double-digit cases. Now, as we enter our second epidemic season, the global epidemic is growing very fast, with hundreds of thousands or even millions of new cases a day. In countries with high outbreaks, there is an urgent need for vaccines to stem the growth of the epidemic, to protect their high-risk populations, and to have a more urgent need for vaccines than we do. Therefore, in accordance with the government's arrangements, orderly vaccination, can cope with domestic prevention and control needs.: Through our evolved immune system, we can develop pre-immunity to infectious diseases and then respond to infections or diseases caused by them. Infectious disease prevention and control, is the three major blocking. One is called to control the source of infection, the source of infection to find out, isolation control it; the second is to cut off the transmission route, block it to infect new susceptible population; the third measure is to protect the susceptible population, through vaccination to make it a certain degree of resistance, vaccination, can have a certain immune barrier in the population to reach a certain proportion of people, the virus or bacteria will be difficult to spread again.
how many people are needed to be immunized in groups, or to build an immune barrier, depends on the ability of a virus or bacteria to spread. A simple formula, 1-1/R0, can be used to calculate the percentage. R0 is called the basic regeneration number, which refers to how many people a person with the virus can infect. The R0 measurement of the new coronavirus is high and low, the average is about 3, that is, a person can pass on about 3 people, calculated (group immunization required vaccination rate) is 66%. At present, the new crown inactivated vaccine has been listed, the protection rate is about 70% to 80% on average. In transport, there may also be some loss. Therefore, it is safer that 80 per cent of the population is vaccinated and the group immune barrier can be achieved.: it is actually influenced by several scientific and technological factors. Over the past year, the scientific community has been reporting secondary infections of the new coronavirus, indicating that the virus is not particularly persistent in some people (a percentage we still have difficult to measure). In other words, the establishment of group immunization is limited by both the high rate of protection of the first vaccines and how long immunity can last after vaccination.: Our people's response to science and government epidemic prevention (measures) is one of the best in the world. There may be some people, considering that China's vaccine protection rate span is relatively large, and some people think that we are using more traditional technology, inactivated vaccine, how safe is it?
from a scientific point of view, it is precisely these two factors do not have to worry. Medically, what drugs and vaccines are safest is through clinical trials. The more people who experiment, the longer the trial will take, and the more safe it will prove. In this sense, the inactivation (technology) used in our country's vaccines has been in use for hundreds of years, and vaccines that have been used by all mankind along this technology route should be said to be reliable.: When we generally do clinical trials of new drug vaccines, we start with young adults because they are more resistant to new drugs. Whether it's Phase I or II, our vaccine classes are required in accordance with this principle when discussing strategies and when reviewing new drugs in the country. As long as the first phase of the young adults (experiment) is safe, it will expand to children at both ends of the age group, the elderly, the sample size of each group is exactly the same.
clinical trials in phases I and II of the new crown vaccine, the final results were safe in all three age groups, with lower side effects in the older group. We also note that home-grown new crown vaccines have been approved for use in many countries and are available to people of all age groups. This shows that the safety of vaccines is guaranteed.
in fact, our country's places for the elderly, such as nursing homes and other elderly services, are very strictly regulated. So we have very few infections in places where older people are concentrated, and in this sense, older people in our country are not at high risk, they are actually less at risk than the general population.: Our country has a very good public health system, from the central to the province, city, county, have all levels of CDC. There are also maternal and child health systems, as well as specialized diseases such as tuberculosis and dermatological control systems, which can be vaccinated. In recent years, health care reform has strengthened the grass-roots level, in the community built a lot of public health service centers, can also be vaccinated. Vaccines have a special traceability code, the entire transport, distribution, use of the process is strictly monitored, so that people can rest assured that they can be near the vaccination.: For example, the measles vaccine we used in the past is very good, and the most powerful vaccine in the past. At that time, there was a high degree of international consensus, driven by the World Health Organization, after about ten to twenty years of efforts, in 1979 to eliminate small flowers. Human activity has unduly made many species extinct, but the only species we have been unthractively extinct is the small-flower virus. Because the death rate from the disease to humans is so high, everyone is afraid that a high degree of consensus can be generated.
we still have to do a good job in science education. For example, our national health work and mass movement, in fact, is to publicize to the public, so that everyone has the concept of public health. Because the prevention and treatment of infectious diseases can only ensure the safety of individuals if everyone is involved and everyone is safe.: The new crown outbreak is now in the second annual epidemic season of the respiratory disease pandemic. Like the Spanish pandemic of 1918, the peak was in early 1919. The same is true now, but I think the momentum will be quickly contained. Because now many countries realize that the prevention and control has not been as well-positioned and thorough as China's, and is now improving, such as the Biden administration's "100-day plan", and (wearing) masks is no longer a matter of debate. These measures, combined with mass vaccinations, will turn the world in a better direction. By then, I think there should be at least 50% weakening of the epidemic. By this summer, when respiratory diseases are not conducive to transmission, the northern hemisphere will stabilize and the world will be able to respond more safely to the outbreak prevention and control this winter and next spring.: Because strain screening doesn't take long, such as two weeks to get a rough result, the entire production cycle is about 40 days. The same is true of the mRNA vaccine, which is actually synthesized on a machine, giving it a new drawing that the machine can do.
other routes, such as recombination proteins and viral vector vaccines, the process is complex and requires dozens of steps to complete. That's why mRNA and inactivated vaccines were first introduced. : The quickest test is to test the vaccine's immune serum in-body directly with different strains of the virus to test its ability to mediat. We've seen antibodies have a better ability to make the mutant strains found in the UK, and a lot more resistant to the strains found in South Africa. Of course, this data does not equal the body's vaccine protection.
response depends on what the dominant strain is prevalent in a region. Existing vaccines are well protected against early epidemic strains in Wuhan, including Italy, France and Germany. (If the dominant strain of the local epidemic mutates) I think we can consider a two-price vaccine: one is a strain of early epidemics, and the other is a new strain that has become more important locally.
think the future development of new crown vaccine will move towards a multi-priced vaccine like the flu vaccine. The flu vaccine uses a four-price vaccine every year, which is to inject different types of mutant strains together. We don't have to panic, science is constantly being studied, data is accumulating, vaccines are not updated, when to update, the government health department will make scientific judgments based on the data.