34 questions about COVID-19 vaccination: authoritative answers from the Chinese Center for Disease Control and Prevention

The Chinese Center for Disease Control and Prevention has published a 34-item FAQ on COVID-19 vaccination on its official website (updated on March 31, 2021). It provides detailed answers to vaccination questions of general concern to the public, ranging from "Is it necessary to get the COVID-19 vaccine?" to "How does the vaccine work in the human body?" to "How to discover and grasp the contraindications of vaccination."

1. Is it necessary to get vaccinated with the new coronavirus vaccine?

It is necessary. On the one hand, the vast majority of people in my country have no immunity against the new coronavirus and are susceptible to it. After infection, some people will develop critical illness or even die. After vaccination, on the one hand, most people can gain immunity, thereby effectively reducing the risk of illness, severe illness and death; on the other hand, through orderly vaccination of the new coronavirus vaccine, an immune barrier can be gradually established among the population, blocking the spread of COVID-19 and restoring the normal operation of my country's social economy and residents' lives as soon as possible.

2. How does the new coronavirus vaccine work in the human body?

After vaccination, the human body will produce protective antibodies, and some vaccines will also cause the human body to produce cellular immunity and form corresponding immune memory. In this way, the human body will have immunity against diseases. Once the new coronavirus invades the human body, the antibodies produced by the vaccine and the cytokines released by cellular immunity can identify, neutralize or kill the virus, and the immune memory will quickly mobilize the immune system to play a role, preventing the virus from continuing to proliferate in the body, thereby achieving the purpose of preventing the disease.

3. How many new coronavirus vaccines have been approved for conditional marketing or emergency use in my country?

my country has approved the conditional marketing or emergency use of COVID-19 vaccines produced by five manufacturers. Among them, three inactivated vaccines and one adenovirus vector vaccine have been conditionally approved for marketing; in addition, one recombinant COVID-19 vaccine (CHO cell) has been approved for emergency use.

4. Which companies have been approved to produce the new coronavirus vaccine?

The three inactivated coronavirus vaccine products that have been conditionally approved for marketing are produced by Sinopharm Beijing Institute of Biological Products Co., Ltd. (Beijing Institute), Wuhan Institute of Biological Products Co., Ltd. (Wuhan Institute) and Beijing Sinovac Biotech Co., Ltd. (Sinovac Biotech).

The adenovirus vector vaccine conditionally approved for marketing is produced by CanSino Biologics Inc. (CanSino).

The recombinant subunit vaccine approved for emergency use is produced by Anhui Zhifei Longcom Biopharmaceutical Co., Ltd. (Zhifei Longcom).

5. How to trace the entire COVID-19 vaccine?

The Vaccine Management Law requires the country to implement a full electronic traceability system for vaccines. After the vaccine is launched, accurate and standardized records should be kept for each link, including production, transportation, storage, transportation, and use. The information recorded during the full traceability process includes vaccine varieties, vaccine manufacturers, dosage forms, specifications, batch numbers, expiration dates, and vaccination case information. Localities use vaccination information technology to timely enter the above information into the system to achieve full electronic traceability of vaccine circulation and use.

6. At this stage, which groups of people are eligible for the new coronavirus vaccine?

The target population for vaccination with the new coronavirus vaccine in my country is people aged 18 and above.

7. How many doses of the COVID-19 vaccines currently approved for use in my country are required? And how long is the interval between doses?

Currently, two doses of inactivated coronavirus vaccine are required; the interval between the first and second doses should be 3 weeks or more, and the second dose should be completed as soon as possible within 8 weeks after the first dose.

Adenovirus vector vaccines require one dose.

The recombinant subunit vaccine requires three doses; the interval between the first and second doses, and the interval between the second and third doses are recommended to be 4 weeks or more. The second dose should be completed within 8 weeks after the first dose, and the third dose should be completed within 6 months after the first dose.

8. Where can I get the new coronavirus vaccine?

The COVID-19 vaccine is administered at vaccination units approved by local health administrative departments. Usually, vaccination units are located in health service centers, township health centers, or general hospitals in the jurisdiction. If the vaccination involves some departments or enterprises with a large number of key targets, the local area will also set up some temporary vaccination units according to the situation.

The local health administrative department or disease prevention and control agency will also announce the vaccination units that can carry out new coronavirus vaccine as required, including location and service hours. Please pay attention to the relevant information release platform.

9. What are the contraindications for vaccination?

Contraindications to vaccination refer to situations in which vaccination should not be given. According to the Technical Guidelines for COVID-19 Vaccination (First Edition), common contraindications to vaccination include: 1. People who are allergic to the active ingredients of the vaccine, any of the inactive ingredients, or substances used in the production process, or those who have had allergies when previously vaccinated with similar vaccines; 2. People who have had severe allergic reactions to vaccines in the past (such as acute allergic reactions, angioedema, dyspnea, etc.); 3. People with uncontrolled epilepsy and other serious neurological diseases (such as transverse myelitis, Guillain-Barré syndrome, demyelinating diseases, etc.); 4. People with fever, or acute illness, or acute exacerbation of chronic diseases, or uncontrolled severe chronic diseases; 5. Pregnant women. Some contraindications, such as fever, are temporary, and the vaccine can be given later when the conditions that cause the contraindications no longer exist.

10. How to discover and grasp the contraindications of vaccination?

During the implementation process, if a severe allergic reaction occurs after the first dose of the vaccine and it cannot be ruled out that the vaccine is the cause, the second dose is not recommended. It is necessary to understand the vaccine ingredients, and those who have a history of allergies to the vaccine ingredients should not be vaccinated.

During vaccination, the recipient must truthfully report his physical health condition, medical history, allergy history, etc. to the vaccinating doctor; the vaccinating doctor will ask about the recipient's health condition and previous allergy history.

11. Can the new coronavirus vaccines from different manufacturers be used interchangeably?

According to the "Technical Guidelines for COVID-19 Vaccination (First Edition)", it is currently recommended to complete the full course of vaccination with the inactivated COVID-19 vaccine from the same company. In the event of special circumstances such as the continued supply of vaccines or vaccination in a different location, when the full course of vaccination cannot be completed with the inactivated COVID-19 vaccine from the same company, inactivated vaccines produced by other companies can be used to complete the vaccination.

12. Where and how is the new coronavirus vaccine administered?

The five approved COVID-19 vaccine administration sites are all the deltoid muscle of the upper arm, and the administration route is intramuscular injection.

13. What should we pay attention to during the new coronavirus vaccine vaccination process?

During the vaccination process, recipients should pay attention to and cooperate with the following matters:

Before vaccination, you should understand the relevant knowledge about the new coronavirus disease, the new coronavirus vaccine and the vaccination process in advance.

When receiving the vaccination, you need to bring relevant documents (ID card, passport, etc.), and take personal protection according to local prevention and control requirements, cooperate with the on-site vaccination staff's questions, and truthfully provide information such as your own health status and vaccination contraindications.

After vaccination, you need to stay for observation for 30 minutes; keep the local skin of the vaccination site clean and avoid scratching the vaccination site with your hands; if suspected adverse reactions occur, report to the vaccination unit and seek medical attention in time if necessary.

14. Why do you need to stay for observation for half an hour after vaccination?

After vaccination, a very small number of people may experience acute allergic reactions, syncope, etc. Acute allergic reactions that seriously endanger life safety often occur within 30 minutes after vaccination. If an acute allergic reaction occurs, timely treatment measures can be taken on the spot. Syncope also mostly occurs within half an hour after vaccination. If you leave the observation site immediately after vaccination, syncope may cause accidental injury to the vaccine recipient. Therefore, the vaccine recipient needs to stay in the designated area of ​​the vaccination unit for half an hour after vaccination.

15. Why is there a certain interval between doses of inactivated new coronavirus vaccine?

Usually, inactivated vaccines need to be vaccinated multiple times to achieve a good immune effect. According to clinical trial data, the first dose of the new crown inactivated vaccine can stimulate the body to produce a partial immune response, and the second dose can produce a better immune effect. The interval between doses generally needs to determine the minimum interval between doses based on the results of clinical trial research. If the two doses are not completed within the time required by the program interval, the vaccination should be supplemented as soon as possible.

16. How to get a booster shot if you have not completed the full immunization program? Do you need to start over?

For vaccines with a two- or three-dose immunization program, it is recommended that those who have not completed the full course of vaccination should receive the unfinished doses as soon as possible. There is no need to restart the vaccination according to the immunization program.

17. Do people who received two doses of inactivated new coronavirus vaccine with an interval of less than 3 weeks need to get a booster shot?

For those who have completed 2 doses of the inactivated COVID-19 vaccine within 14 days, a booster dose of the inactivated vaccine should be given as soon as possible 3 weeks after the second dose. For those who have completed 2 doses of the inactivated COVID-19 vaccine within 14-21 days, no booster dose is required.

18. After completing the full course of inactivated coronavirus vaccine, is it necessary to strengthen immunity?

Booster immunization is not recommended at this stage.

19. After receiving the inactivated new coronavirus vaccine, if you still want to get vaccinated with vaccines of other technical routes, is this practice scientific?

Currently, the inactivated COVID-19 vaccine requires two doses of immunization. Whether booster immunization is needed after two doses of inactivated vaccine immunization, and whether other vaccines can be used for booster immunization, needs further study.

20. It has been suggested that HPV vaccine and new coronavirus vaccine cannot be administered at the same time. How long should the interval be?

The COVID-19 vaccine is a new vaccine. In order to facilitate identification or differentiation of possible suspected adverse reactions to the vaccine, it is not recommended to administer the COVID-19 vaccine at the same time as other vaccines (including HPV vaccines). However, this does not mean that other vaccines cannot be administered after the COVID-19 vaccine. It is just recommended that the COVID-19 vaccine and other vaccines be administered at least two weeks apart. It must be noted that when rabies vaccine, tetanus vaccine, or immunoglobulin is urgently administered due to animal injuries or trauma, the interval between the COVID-19 vaccine and the vaccination is not considered.

21. Can women of childbearing age and breastfeeding women receive the new coronavirus vaccine?

If you become pregnant after vaccination or are vaccinated without knowing you are pregnant, based on our understanding of the safety of the vaccine, we do not recommend taking special medical measures (such as termination of pregnancy) solely because of the COVID-19 vaccine. We recommend that you do a good job of pregnancy checkups and follow-up. For women who are planning to get pregnant, there is no need to delay their pregnancy plans just because of the COVID-19 vaccine.

Although there is currently no clinical research data on the impact of COVID-19 vaccines on breastfeeding infants and young children during breastfeeding, based on our understanding of vaccine safety, it is recommended that breastfeeding women at high risk of COVID-19 infection (such as medical staff) be vaccinated. Considering the importance of breastfeeding to the nutrition and health of infants and young children, and referring to international practices, it is recommended that breastfeeding women continue breastfeeding after receiving COVID-19 vaccines.

22. Can people aged 60 and above receive the new coronavirus vaccine?

People aged 60 and above are at high risk of severe illness and death after being infected with the new coronavirus. At present, the number of people in this population is limited in the Phase III clinical trials of the four conditionally approved new coronavirus vaccines, and the Phase III trials of the recombinant subunit vaccine are still in progress. There is no data on the protective efficacy of the vaccine for this population. However, the data from the Phase I/II clinical studies of the above-mentioned vaccines show that the vaccination safety of this population is good. Compared with the 18-59 age group, the neutralizing antibody titer after vaccination is slightly lower, but the neutralizing antibody positive conversion rate is similar, indicating that the vaccine will also have a certain protective effect on people over 60 years old, and vaccination is recommended.

23. Can people under the age of 18 be vaccinated with the new coronavirus vaccine at this stage?

Currently available vaccines have not yet obtained clinical trial data for use in this population, and vaccination is not recommended for people under the age of 18.

24. Can people with chronic diseases receive the new coronavirus vaccine?

People with chronic diseases are at high risk of severe illness and death after being infected with the new coronavirus. People with chronic diseases whose health conditions are stable and well controlled by medication are not considered as people who are contraindicated for the new coronavirus vaccination and are recommended to be vaccinated.

25. Can people with impaired immune function receive the new coronavirus vaccine?

People with impaired immune function are at high risk of severe illness and death after being infected with the new coronavirus. There is currently no data on the safety and effectiveness of the new coronavirus vaccine for this group of people (such as patients with malignant tumors, nephrotic syndrome, and AIDS) or people infected with the human immunodeficiency virus (HIV). The immune response and protective effect of this group of people after vaccination may be reduced. For inactivated vaccines and recombinant subunit vaccines, vaccination is recommended based on the safety characteristics of previous vaccines of the same type; for adenovirus vector vaccines, although the vector virus used is replication-deficient, there is no previous safety data for the use of vaccines of the same type. It is recommended that vaccination be made after the individual has been fully informed and has weighed the benefits against the risks.

26. Do people who have been infected with the new coronavirus still need to be vaccinated against the new coronavirus?

Existing research data shows that reinfection within 6 months after COVID-19 infection is rare. People who have been infected with COVID-19 (patients or asymptomatic carriers) can receive one dose of the vaccine 6 months later, provided they are fully informed.

27. How long does it take to produce antibodies against the new coronavirus after being vaccinated with the inactivated new coronavirus vaccine?

According to previous clinical trials of inactivated coronavirus vaccines, the vaccinated population can produce a better immune effect about two weeks after the second dose of the inactivated vaccine.

28. Is it necessary to test antibodies before and after vaccination?

There is no need to conduct nucleic acid and antibody tests for the new coronavirus before vaccination; it is also not recommended to conduct routine antibody testing after vaccination as a basis for whether the immunization is successful or not.

29. Do I need to take a nucleic acid test after receiving the new coronavirus vaccine? Can the vaccination certificate replace the nucleic acid test report?

After receiving the new coronavirus vaccine, a very small number of vaccine recipients may still test positive for nucleic acid or become ill due to protection failure due to the following reasons: 1. After the full vaccination, some people fail to obtain effective protection due to immune failure. After these people are exposed to the new coronavirus, they may test positive for nucleic acid or become ill due to infection with the new coronavirus. 2. It takes some time for the vaccine to produce a protective effect. If you are infected with the new coronavirus during this period, you may test positive for nucleic acid or become ill. 3. Patients in the incubation period of the disease or asymptomatic infected people may still test positive for nucleic acid or become ill due to infection even if they are vaccinated.

The above-mentioned people may become infected people. When nucleic acid screening is required for the prevention and control of the new crown epidemic, the new crown virus vaccination certificate cannot replace the nucleic acid test report, and nucleic acid testing must be carried out in cooperation with relevant departments.

30. After the new coronavirus mutates, will the new coronavirus vaccine still be effective?

Judging from the global monitoring of the new coronavirus mutation, there is currently no evidence that the virus mutation will make the existing new coronavirus vaccine ineffective. Viruses are one of the simplest organisms, and their proliferation depends on living cells. During the proliferation process, viruses will mutate. The World Health Organization, research institutions in various countries, vaccine manufacturers, etc. are closely monitoring the mutation of the new coronavirus and are also conducting related research, which will provide early warning and scientific analysis basis for the subsequent development and application of vaccines.

31. What does suspected abnormal reaction to vaccination mean? What situations does it include?

Suspected adverse events following immunization (AEFI) refers to reactions or events suspected to be related to immunization that occur after immunization, also known as suspected adverse reactions to vaccines. They include the following situations: adverse reactions to vaccines, reactions related to vaccine quality issues, reactions related to vaccination errors, psychogenic reactions, and coincidental diseases (coincidental reactions).

32. What are the common adverse reactions to the new coronavirus vaccination?

Based on the results of the previous clinical trials of the COVID-19 vaccine and the information collected during emergency use, the incidence of common adverse reactions to the COVID-19 vaccine in my country is basically similar to that of other widely used vaccines. Common adverse reactions mainly include redness, swelling, nodules, and pain at the injection site, as well as fever, fatigue, nausea, headache, and muscle aches. Relevant departments will continue to strengthen real-time monitoring and evaluation of adverse reactions in the future.

33. What are the differences between general reactions and abnormal reactions to vaccination?

Both general reactions and abnormal reactions are adverse reactions to vaccines, which are caused by the characteristics of the vaccine itself and are unrelated to the purpose of vaccination or are unexpected reactions, and are related to individual differences in the vaccine recipients. The two are different in the following aspects:

1. Frequency and severity of occurrence: General reactions account for the vast majority of adverse reactions. They are transient, mild reactions of the body and usually do not require treatment. Abnormal reactions mainly refer to reactions that cause damage to the recipient's organs or functions. They rarely occur and often require treatment. 2. Clinical manifestations: General reactions generally manifest as local reactions such as redness, swelling, nodules, and pain at the injection site, and systemic reactions such as fever, fatigue, and headache. Abnormal reactions often manifest as acute severe allergic reactions. 3. Whether a report is required: Most of the lighter general reactions do not need to be reported; suspected serious abnormal reactions need to be reported. 4. Investigation and diagnosis: General reactions usually do not require investigation and diagnosis; suspected serious abnormal reactions need to be investigated and diagnosed by an investigation and diagnosis expert group organized by a disease control agency. If there is any objection to the investigation and diagnosis conclusion, it can be identified by an appraisal expert group organized by a municipal or provincial medical association.

34. Will our prevention and control measures be adjusted after vaccination begins?

For individuals, the protective effect of vaccination is not 100%, and it takes a certain amount of time to produce protective antibodies; for the group, the new coronavirus is still easy to spread without forming an immune barrier. Therefore, to prevent the rebound of the new coronavirus epidemic, some prevention and control measures must still be adhered to at this stage, including wearing masks, maintaining social distance, washing hands frequently, ventilation and other protective measures. The new coronavirus epidemic prevention and control measures for the population will be adjusted in a timely manner as the coverage rate of the new coronavirus vaccine population increases and the epidemic situation of the disease changes at home and abroad.