Reports on Suspected Adverse Reactions to COVID-19 Vaccines and the Health Damage Relief System for Immunization
Adverse Reactions to the COVID-19 Vaccination
The main adverse reactions reported after getting vaccinated with Pfizer/Comirnaty or Takeda/Moderna include Pain at the inoculation spot, fatigue, headache, muscle pain and joint pain. Although the results of different clinical trials cannot be simply compared, the frequency of side effects with Takeda/ Moderna has been reported to be 5 to 20 percentage points higher than with Pfizer. In addition, delayed skin reactions (the so-called "COVID arm" or "Moderna arm"), in which pain and swelling of the inoculated spot are seen about one week after vaccination, have been reported. Most people with these symptoms recover within a few days after vaccination. In addition, given the high efficacy of both vaccines, it is recommended to receive either vaccine when available, rather than focusing on the difference in frequency of these minor adverse reactions.
|expression rate||Symptoms of Pfizer/ Comirnaty||Symptoms of Takeda/Modena|
|50％ and up||Pain at the inoculation site, fatigue and headache||Pain at the inoculation site, fatigue, headache and Muscle pain|
|10% - 50%||Muscle pain, chills, joint pain, diarrhea, fever and swelling of inoculation site||Joint pain, chills, Nausea and vomiting, lymphadenopathy, fever, swelling of inoculation site and erythema|
|1% - 10%||Nausea and vomiting||Pain at the vaccinated spot after 7 days after inoculation, etc.*|
Reports on suspected adverse reactions to COVID-19 vaccines
The Ministry of Health, Labour and Welfare (MHLW) requested medical institutions to report suspected cases of adverse reactions to COVID-19 vaccines so that they can collect data.
Among these reports, there are many cases where it is not clear whether adverse reactions are caused by vaccines or something else, or whether symptoms happened to develop soon after vaccination, though they had nothing to do with it. We make these reports available to the public including above-mentioned cases.
Please refer to the Q&A section regarding adverse reactions by the MHLW:
|The number of reported cases||Main symptoms of adverse reaction|
|50 cases||Headache, fever, chills, palpitations, dizziness, numbness, hives, etc.|
Those vaccinated or their parents/guardians are able to report cases of suspected adverse reactions or health damage after vaccination to a municipal government if necessary. Please refer to “other points to note” section in the link below and inquire to the COVID-19 Vaccination Distribution Office of Tsukuba City.
There is also a system for parents/guardians to directly report cases of possible adverse reactions to the Pharmaceutical and Medical Devices Agency (PMDA). Please find the details in the link below:
FAQ about Adverse Reactions
- What should I do if I develop a fever after receiving a vaccine?
- A fever from vaccination often occurs within a day or two after getting vaccinated. Please drink plenty of fluids, take medicine to reduce fever and/or to relieve pain if necessary, and monitor your condition.
- Can I take over-the-counter antipyretic analgesics for fever and pain after receiving the vaccine?
Over-the-counter antipyretic and painkillers can be used to treat fever and pain after receiving the vaccine, but please consult your doctor or pharmacist, especially in the following cases
・You are taking other medicine, pregnant, breastfeeding, elderly or under treatment for diseases such as gastric or duodenal ulcers, or decreased kidney function. (Some medicine cannot be mixed with other types of medicine.)
・You experienced an allergic reaction or asthma in the past after taking medicine.
・Severe symptoms such as severe pain or high fever, or symptoms that last for a long time.
・Symptoms that are not typical after vaccination.
Please note that it is not recommended to repeatedly take medicines to reduce fever and/or relieve pain to prevent possible adverse reactions before they develop.
Vaccination Health Damage Relief System for cases of adverse reactions after vaccination
In general, although health damage (illness or disability) caused by adverse reactions to vaccinations are extremely rare, because it cannot be eliminated completely, relief systems are in place.
In the relief system, when a person suffers from health problems caused by vaccination and needs medical treatment or is left with a disability, they can receive relief (medical expenses, disability pension, etc.) based on the Immunization Law.
With regard to COVID-19 vaccine, if any health damage occurs, you can receive relief based on the Immunization Law.
For more information about the current relief system, please refer to the "Vaccination Health Damage Relief System" (Only available in Japanese) below.
- The Health Damage Relief System requires a period of time to be approved, as it is necessary to check the application documents and hold a review meeting for the applied cases.
- The applicant is responsible for the cost of obtaining all documents and materials related to the application. In addition, there is a possibility that additional materials may need to be submitted after the application. In this case as well, you will be responsible for the cost of obtaining the additional materials.
Contact information for notifications of health problems after vaccination