Analysis of donated blood by the National Institute of Infectious Diseases revealed that 28.6% of people nationwide had antibodies caused by infection with the new coronavirus as of November this year.
Antibody prevalence decreases with age, and regular vaccination is considered necessary.
The National Institute of Infectious Diseases and others examined the blood of 8,260 people aged 16 to 69 who visited blood donations in early November this year, and analyzed the percentage of people who have antibodies that can only be obtained when infected with the new corona. .
According to it, the antibody possession rate was 28.6% nationwide, and as of March this year, the proportion of infected people in five prefectures such as Tokyo and Osaka was estimated to be 4.3%, which is higher than that. It indicates that the number of infected people may have increased significantly since the 7th wave.
By age group,
▽ 16 to 19 years old 38.9%
▽ 20s 40.4%
▽ 30s 34.9%
▽ 40s 29.1%
▽ 50s 21.8%
▽ 60s 17.0%, which
tends to decrease as the age increases. I was seen
In addition, while Okinawa Prefecture was 45.1%, Osaka Prefecture was 43.0%, and Tokyo was 34.5%, there were differences such as 9.2% in Nagano Prefecture, 13.2% in Tokushima Prefecture, and 14.2% in Niigata Prefecture. .
Motoi Suzuki, director of the Center for Epidemiology of Infectious Diseases at the National Institute of Infectious Diseases, said, ``Immunity weakens over time, and there is a high risk of expecting immunity from infection. It is thought that it is necessary to continue