The website of the Ministry of Health, Labor and Welfare provides information about the new coronavirus vaccine, including information about the new coronavirus vaccine, information about the vaccine, answers to questions, and notices for everyone involved in vaccination.

• About the new corona vaccine (Ministry of Health, Labor and Welfare website)
• English: COVID-19 Vaccines (Ministry of Health, Labor and Welfare website)
• Notice (Ministry of Health, Labor and Welfare website) about vaccination for children aged 6 months to 4 years old (infant vaccination)
• New Corona Vaccine Q&A Infant vaccination (6 months to 4 years old) (Ministry of Health, Labor and Welfare website)

effects and side effects

effect

Approximately 1,100 infants were analyzed to see how much the new coronavirus vaccine would reduce symptoms even if they were infected with the new coronavirus (prevention effect), and the results were 7 after the third vaccination. Effectiveness after the day is reported to be 73.2 percent.
For more information, please see the Q&A on the new coronavirus vaccine, "What are the effects of vaccination for infants (6 months to 4 years old)?" (Ministry of Health, Labor and Welfare website) .

side reaction

In a clinical trial investigating symptoms after vaccination, when looking at the specific symptoms after the first to third vaccinations, there was not much change in symptoms depending on the number of vaccinations, and most of the symptoms were mild or moderate. . Based on the information available at this time, no serious safety concerns have been identified. For details, please refer to the Q&A on the new coronavirus vaccine, "What are the side effects of vaccination for infants (6 months to 4 years old)?" (Ministry of Health, Labor and Welfare website) .

List of symptoms by age

age	Symptoms (Occurrence ratio: 1st vaccination → 2nd vaccination → 3rd vaccination) (unit is percent)	Symptoms (Occurrence ratio: 1st vaccination → 2nd vaccination → 3rd vaccination) (unit is percent)
6 months to 1 year old	Irritability (Note 1) 51.2 → 47.4 → 43.6 Decreased appetite 22.2→22.2→20.2 Somnolence (Note 2) 27.0 → 23.8 → 19.9 Tenderness 16.6→15.0→16.0	Fever 7.2→7.4→6.8 Swelling 3.9→3.9→2.7 Redness 10.6→9.3→7.1
2 to 4 years old	Pain 30.8→31.0→26.7 Fatigue 29.7→25.7→24.5 Redness 8.8→11.4→10.9 Diarrhea 7.7→6.7→5.1 Fever 5.2→4.9→5.1 Headache 4.5→4.6→4.9	Swelling (Note 3) 3.7→5.7→3.1 Vomiting 3.0→3.4→1.6 Chill 2.3→3.0→3.3 Muscle pain 2.4→2.6→2.0 Joint pain 0.8→1.4→1.3

(Note 1) bad mood
(Note 2) Feeling sleepy
(Note 3) Swelling at the injection site Quoted from: Ministry of Health, Labor and Welfare pamphlet "Notice about new corona vaccination (for parents of children aged 6 months to 4 years old)"