All your questions about COVID-19 vaccination answered

Hu Min Cai Wenjun
Vaccines will be given first to priority groups with high potential infection risks.
Hu Min Cai Wenjun

Shanghai has started inoculating key groups with COVID-19 vaccines. The Shanghai Center for Disease Control and Prevention issued a Q&A for questions that concern many people.

Q: Who are the priority groups for COVID-19 vaccination?

A: Vaccines will be given first to priority groups with high potential infection risks. These include inspection and quarantine customs staff engaged in handling imported cold-chain products, baggage workers at ports, staff involved in international and domestic transportation, those who will work or study overseas, those working at frontier ports exposed to overseas infection hazards, medical workers, government officials, police, firefighters, community workers and people whose work is related to logistics, senior care, public sanitation, public utility, transportation, funeral and interment, and telecommunications.

Q: What are the vaccines used in Shanghai?

A: They are inactivated virus vaccines. Using chemical means, they curb infection and replication of the COVID-19 virus, and trigger human immune response activity.

The vaccines are based on traditional and classic vaccine preparation methods, which originate in mature and reliable research and development.

Compared with other technical means, the platform of inactivated virus vaccine research and development is mature and its manufacturing technique is stable. Its quality standard can be controlled and it has good protection. It can be mass produced, and its safety and effectiveness are recognized by the international society.

Q: How many doses should be given?

A: The vaccination drive is in two steps, with an interval period of at least 14 days. It should be given on the deltoid. Random adjustment of inoculation procedures will probably affect the vaccines' safety, effect and duration of immunization.

Q: Who are not advised to take the vaccine?

A: The following groups at the current stage.

1. People who are allergic to any substance of vaccines and who have showed serious allergic symptoms such as acute allergy, urticaria, eczema, expiratory dyspnea, angioneurotic edema and abdominal pain to vaccines in the past.

2. Those with fever, acute disease, serious chronic disease, and patients who are in the acute stage of chronic disease.

3. Those in pregnant or lactation period or with pregnancy plan within three months of vaccination.

4. People who have history of convulsions, epilepsy, brain or mental diseases or have such history in their families. Patients with uncontrollable epilepsy or nervous system diseases, or the history of guillain-barre syndrome.

5. Those who have been diagnosed with congenital or acquired immunodeficiency syndrome, HIV infection, lymphoma, leukemia, or other autoimmune diseases.

6. Confirmed or suspected cases of serious respiratory diseases, severe cardiovascular diseases, liver and kidney diseases or malignant tumor.

7. Those who use immunomodulators such as anti-tumor drug.

8. Those who have the history of COVID-19 virus infection.

9. Anyone who is deemed not proper to take the vaccination by clinicians.

Q: Can COVID-19 vaccines be given together with HPV vaccine?

A: Based on past experience, inactivated virus vaccine can be given with other vaccines. However, it is suggested to separate the inoculation of the COVID-19 vaccines and other vaccinations due to lack of relevant research.

Those who have been inoculated with other inactivated virus vaccines within 14 days or live-attenuated vaccines within 28 days should delay the inoculation of COVID-19 vaccines.

Q: Are the COVID-19 vaccines safe given the research and development was pronounced a success in such a short time?

A: Like other vaccines, the COVID-19 vaccines have undergone a number of tests on animals and humans, as well as clinical tests to prove its safety.

Q: Are there any adverse reactions after people are inoculated with the COVID-19 vaccines?

A: Like any other vaccine, people will probably show some common reactions after they take the inactivated virus vaccines, such as soreness, red and swollen, pain and pruritus on the inoculation parts, and few may show symptoms such as fever, fatigue, nausea, headache and muscle pain. These symptoms will disappear after two to three days for most people without intervention.

No serious adverse reactions to the vaccines have been observed so far.

The vaccines may trigger allergic reactions, which is natural to vaccines, and relevant adverse reactions do not mean that there are problems in the quality and safety of COVID-19 vaccines. 

Q: Why do people sometimes have a cold or fever after being injected with vaccine?

A: It can be coincidental event, which means that the vaccine reception is in the incubation period or early stage of certain disease when he or she is receiving the vaccination and develops symptoms after the shots. A coincidental event is not caused by vaccination and has no causal relation with vaccination.

Q: What are necessities before and after vaccination?

1.  Please tell doctors the true health condition before receiving a COVID-19 vaccine.

2.  Please stay at the site for 30 minutes for medical observation after receiving vaccination. The place of the injection should be kept clean and dry. People should have a good rest and avoid contacts with personal allergens and common allergens, avoid alcohol and spicy food as well as seafood. A light diet and drinking plenty of water are suggested.  

Q: How to report serious adverse reaction after receiving vaccination?

A: According to experiences, serious adverse reaction usually takes place within 30 minutes after vaccination. People should tell doctors in time. There are professionals at the vaccination site to offer treatment. There are two district- or city-level hospitals in each district to be designated to treat adverse reaction after vaccination.

Q: How long will antibodies appear after vaccination?

A: Clinical research found people usually generate antibodies seven days after receiving the first dose, and 60 to 90 percent have an antibody positive rate between 14 and 28 days after the shots. The antibody positive rate is over 90 percent 28 days after receiving the second dose and the protection remains.

Q: Can people still contract COVID-19 after receiving vaccination?

A: According to the result of double-blind phase-I and II clinical trials of the inactivated vaccine used in this round of inoculation, there are high antibody responses, with over 90 percent antibody positive rate. The phase-III clinical trial conducted by multiple countries in the world have also further testified the effects.

However, no vaccines can achieve a 100 percent protection rate. A small number of people may not develop protection after receiving vaccine or still develop the disease. These are related to the vaccine’s own features and the person's physical condition.

Q: Is the vaccine effective against mutated COVID-19 virus or virus from other countries?

A: Cross-neutralization tests on known mutated COVID-19 virus strains and strains from countries like the United States, the UK, Russia and Austria show that this inactivated vaccine can completely neutralize the viruses. The vaccine is effective against both mutated virus and virus from other countries.

Q: How long does the protection remain?

A: Novel coronavirus was discovered less than one year, so the immunity durability for inactivated vaccine is still under observation. Current evidence shows the protection will remain at least six months.

Q: Will nucleic acid tests show positive after receiving the vaccination?

A: No. Nucleic acid test checks the antigen of coronavirus. This vaccine is inactivated vaccine, which means a killed pathogenic microorganism that has completely lost the ability of infection and reproduction. So people won’t catch coronavirus through vaccination.

Q: Will serum antibody tests show positive after receiving the vaccination?

A: The effects of vaccination are to stimulate the body to produce antibodies. Antibodies are positive 28 days after people with two doses of inactivated COVID-19 vaccines during the phase-I and II clinical trials and people with emergency inoculation.

For facilities which don’t have the ability to do cross-neutralization tests and use common methods like colloidal gold test or enzyme-linked immunosorbent assay, the result of antibodies may be negative. It is related to the sensitivity of test methods and may not show that people don’t have immunity response.

Q: Is it necessary to do nucleic acid test after vaccination? Can a vaccination certificate take the place of nucleic acid test report?

A: Vaccination can reduce the risk of infection but no vaccine can ensure 100 percent protection. It is necessary to cooperate with authorities to receive nucleic acid test.

Q: What should people do if an antibody test shows positive at the exit-entry border after receiving vaccination?

A: This inoculation uses inactivated vaccine. A person can show the vaccination paper if antibody test is positive but nucleic acid test is negative in medical checks at home and abroad.

Q: It is necessary to wear a mask after receiving the vaccination?

A: So far, no vaccine can ensure a 100 percent protection. A small amount of people may not produce protection or still develop the disease. The immunity barrier in the population hasn’t been built up. So self-protection like wearing a mask, washing hands, keeping social distance are still necessary after vaccination.

Q: Can people take this vaccines to their overseas colleagues?

A: There are strict procedures for exit and entry of COVID-19 inactivated vaccine. Individuals are not allowed to take the vaccine overseas personally. It is illegal.

Q: When will ordinary people receive vaccination?

A: According to a recent news conference, China has launched five technical routes to push vaccine development after the coronavirus epidemic. So far, according to the World Health Organization, China is in the leading position concerning vaccines entering clinical trials and vaccines in phase-III clinical trials.

Because the coronavirus epidemic is under control in China, the nation doesn’t meet the criteria for phase-III trial. So five vaccines in phase-III trials are all being tested in other countries. The results will be publicized in time after the double-blind tests are complete. If the data meets the standard, China’s drug administration will approve the marketing. At that time, ordinary people can receive vaccination in accordance with the regulation and vaccine supply.

Shanghai will kick off inoculation for people who should go abroad for personal reasons in the future.

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