Looking at vaccines from a professional point of view, the national immunization experts answered six questions about vaccines.

Xinhua News Agency, Beijing, March 23rd (Reporter Hu Hao)The case of illegal operation of vaccines in Shandong has recently aroused public concern about vaccines: what will happen if vaccines are not transported through the cold chain? Worried that the vaccinated vaccine is invalid, do you want to replant it? What’s the difference between the first-class vaccine and the second-class vaccine in transportation and use? At the media forum organized by the National Health and Family Planning Commission on the 23rd, experts from China’s immunization program answered questions of general concern.

Why should vaccines be refrigerated? How terrible is a vaccine that is not refrigerated?

Zhao Kai, academician of China Academy of Engineering and chairman of the National Committee of Experts on Immunization Planning: Vaccines are biological products made by various pathogenic microorganisms. Some vaccines are attenuated viruses, for example, the main component of measles vaccine is attenuated measles virus, which is alive; Have a plenty of inactivated vaccine, after the bacteria are inactivated, it is an active protein, which plays an immune function.

Therefore, vaccines are delicate. For example, vaccines are afraid of heat and light, and sometimes some vaccines are afraid of freezing. In order to keep the vaccine active, cold chain should be used in transportation.

Generally speaking, if there is no cold chain during the storage and transportation of the vaccine, the activity of the vaccine will be affected more or less, but it is also related to the length of time and temperature outside the cold chain.

As for whether vaccines that have not been transported by cold chain will have adverse vaccination reactions, two factors need to be integrated. One is to investigate the cold chain situation of illegal vaccine transportation, and the other is to investigate the monitoring situation of the information management system for suspected adverse vaccination reactions.

Wang Huaqing, MD, Chief Physician of China Center for Disease Control and Prevention: Theoretically, the vaccine involved is a vaccine produced by a regular manufacturer, not a fake vaccine or a fake vaccine. It has quality control in the early stage, and the safety risk will be less. The impact of not having cold chain transportation in the later period needs to be evaluated.

What is the relationship between class I vaccine and class II vaccine? What’s the difference between management?

Wang Huaqing: A class of vaccines includes three situations. First, 14 vaccines designated by the state prevent 15 diseases. Second, the increase of the provincial health administrative department is included in the national immunization plan. The third is the emergency immunization organized by the government. For example, if there is an epidemic, emergency immunization is needed, or it is possible to predict that the disease will become popular and organize group vaccination, which all belong to the first type of vaccine.

The first type of vaccine is vaccinated free of charge; The second kind of vaccine is self-funded and voluntary.

The management of the second type of vaccine is technically the same as that of the first type of vaccine. The technical requirements are the same whether in circulation or use. However, its procurement methods are different and its supply channels are different. The procurement of the first type of vaccine is carried out by the government, and then distributed step by step through the disease control system, and finally to the inoculation unit. The second type of vaccine is based on the regulations on the management of vaccine circulation and vaccination. Production enterprises can supply it directly to business enterprises, or to disease control departments and vaccination units. Business enterprises can supply disease control institutions, vaccination units or other business enterprises. So the channels are different.

Is there any difference in quality between domestic vaccines and imported vaccines?

Zhao Kai: The technological level of domestic vaccines is completely similar to that of foreign countries. In particular, the quality of vaccines, China’s 2010 edition pharmacopoeia and the European Union’s pharmacopoeia standards are the same. Some domestic vaccines and imported vaccines have been compared or observed, and they are all the same.

Every batch of vaccines produced in China must undergo compulsory inspection and audit before they are put on the market, which is called "batch inspection". Those that fail are not allowed to go on the market. I think this quality is guaranteed.

Wang Huaqing: Actually, domestic vaccines and imported vaccines require the same standards, and they will not enter the market until they reach the standard. Most of our country uses domestic vaccines, and the control of infectious diseases in China is the contribution of domestic vaccines. If there is no domestic vaccine, the control of polio, hepatitis B and measles in China will not be so good. These are all the effects obtained by inoculating children with our own vaccines. Therefore, the final evaluation depends on whether the disease has been controlled after the application of the vaccine and whether its suspected abnormal reactions have increased. In fact, from our monitoring, there is no big difference between domestic and imported vaccines.

How to deal with vaccines near the shelf life? Is it possible to vaccinate the public with expired vaccines?

Han Cheng, director of Desheng Community Health Service Center in Xicheng District, Beijing: As a primary health service center, our vaccine procurement path is very strict, and there are also strict regulations on the validity period. Drugs that have expired in the past six months cannot enter the procurement and distribution system, and the system will automatically block them. It is impossible to enter the organization. In addition, the purchase of vaccines is on a monthly basis, and one batch is used up before entering the second batch, and it is cleaned once a month, and it is uniformly distributed and purchased by the Beijing Center for Disease Control and Prevention.

How do I know if my vaccine is a problem vaccine? Can it be traced back?

Han Chengcheng: The batch number of the vaccine can be traced back. Each child has a batch number corresponding to each medicine, which can be checked. Therefore, it can be traced back to which child a batch number was hit. The validity period of the vaccine, the time of vaccination, etc. are also completely traceable.

Wang Huaqing: When the vaccine enters the disease control system, there will be a receipt form, when it was delivered, the process of delivery, its temperature, the varieties delivered and the quantity, all of which have a complete receiving record. In the process of use, there are two records, including the parents’ signature, when and what vaccine the children took, which company and the batch number. One is the vaccination certificate in the hands of the parents, and the other is the record or vaccination card of the electronic information system.

Is it necessary to confirm whether the vaccine is effectively vaccinated by antibody testing? Is it necessary to replant the vaccine?

Wang Huaqing: If you were not vaccinated in childhood, when should you replant? Different vaccines are different, which needs to be judged again.

We are all very concerned. Did I succeed after the vaccination? The international general principle is that there is no need for testing, because if the vaccine reaches a high vaccination rate, the whole population will have a barrier.

Vaccination, under normal circumstances, does not mean that everyone produces protection, because the main function of vaccine is a group. For example, if 80% to 85% of polio is successful after taking sugar pills, polio will be blocked and eliminated.

If everyone is vaccinated, we will build this crowd barrier. If some people are vaccinated and some people are not vaccinated, the disease may become popular in the future. Therefore, to control an infectious disease, we must maintain a very high vaccination rate in vaccination, especially in the use of vaccines in the national immunization program. If the vaccination rate is not high, then the disease will become popular.