12 Serious Questions to Side Effects or Adverse Reactions After Getting Covid Vaccine

Even though Covid-19 has been with us for quite some time, many people still have questions about it. So, we’ve gathered together all the questions people still have about Covid-19 and come up with clear answers, as follows:

1. What are the benefits of Covid-19 vaccinations?

• They build immunity to the virus which reduces risk of infection and spreading.
• They reduce the severity of the symptoms and the mortality rate if the virus is contracted.
• They build ‘herd’ or population immunity, reducing the opportunity for the virus to spread, and restoring normal conditions in the populace.

2. Can vaccination prevent catching Covid-19?

• Current studies indicate that vaccination may not prevent Covid-19 infection 100% but does prevent severe symptoms. People who have been vaccinated can still be infected with asymptomatic or mild Covid-19 symptoms. As such, it is still necessary to strictly follow preventive measures even after vaccination.

3. If infected with Covid-19 and cured, is it necessary to get vaccinated?

• Even if you have been infected with Covid19, there is still a certain risk of being re-infected. It is therefore recommended for infected persons to be vaccinated at around three months after recovery. However, in this case, one dose should be enough.

4. What should you do if a family member is infected with Covid-19?

• If someone in your family shows symptoms, you should immediately contact the Covid-19 Hotline at 1668, the National Institute for Emergency Medicine at 1669, the Department of Disease Control at 1422, or the National Health Security Office at 1330, and inform the staff who will then arrange for assessment and treatment.
• While waiting for treatment, home Isolation should be implemented by isolating the infected person in a separate room. He or she must avoid close contact with uninfected others. Keep the infected person’s personal belongings, food and drink utensils and clothes separate. Use alcohol spray on hands and items handled by the infected person to prevent transmission to others.
• You can continue to live with the infected person if they are categorized as a “green” patient, provided you strictly follow the home isolation measures.

5. Can you have other vaccinations along with Covid-19 vaccines?

• Not enough study has been done on this to be sure, so wait at least two weeks after Covid-19 vaccination before having any other vaccinations.
• You can get other vaccinations without having to wait, except in the cases of rabies, tetanus and some other vaccines. If unsure, consult your doctor.

6. Can women be vaccinated while they are menstruating?

• Yes, they can have Covid-19 vaccinations as normal.

7. If you have been vaccinated and then find out you are pregnant, what should you do?

• Studies show that Covid-19 vaccines are not harmful to unborn babies so there is no need to worry. Unless there is a severe allergic reaction after the first dose, the second vaccination can be done after 12 weeks of gestation. However, you should consult your doctor before vaccination.

8. Can expectant mothers be vaccinated?

• Expectant mothers can get vaccinated after 12 weeks of gestation. Data from the US Centers for Disease Control and Prevention (CDC)’s V-safe project, collected from more than 94,000 pregnant women who received Pfizer and Moderna mRNA vaccines, did not find any abnormalities caused by the vaccines in either mothers or unborn babies. Therefore, pregnant mothers can be vaccinated safely. However, you should consult your doctor before vaccination.

9. Can breastfeeding mothers be vaccinated?

• Breastfeeding mothers can get all types of vaccines. There is no need to stop breastfeeding after vaccination as there are no reports that the Covid-19 vaccine contains substances that are unsafe for breastfeeding mothers. However, you should consult your doctor before vaccination.

10. What are the side effects of Covid-19 vaccines?

• Swelling, redness, and pain are often present at the injection site. However, the symptoms are not severe and go away on their own.
• There may be mild fatigue, fever, nausea or headache which go away on their own.
• To observe if you have any serious allergic reaction, you should sit in the resting area at the vaccination site for 15-30 minutes after getting vaccinated.
• If you observe any abnormal symptoms within 4 weeks after vaccination, and you are not sure if it is caused by the vaccine, you should consult your doctor immediately

11. How should you prepare for vaccination?

• Behave normally, get enough rest, stay calm, and don’t stress.
• If you get ill, vaccination should be postponed until you recover.
• If you regularly take migraine drugs, antidepressants, NSAIDs (nonsteroidal anti-inflammatory drugs) or dietary supplements, you should stop taking them prior to vaccination.
• No need to refrain from tea, coffee and soft drinks but should refrain from alcoholic beverages.

12. If you have a severe allergic reaction after having the first dose, should you still get the second dose?

• People can have different reactions to the vaccines. If you have a severe reaction to your first dose, consult your doctor about changing the type of vaccine for your second dose.


• Department of Disease Control
• King Chulalongkorn Memorial Hospital, the Thai Red Cross Society
• Department of Mental Health, Ministry of Public Health (Slide no. 64)
• Faculty of Medicine, Chiang Mai University
• Synphaet Hospital
• Department of Mental Health