Study: Some 4.3% Of People In Tokyo, 4 Other Prefectures Contracted Coronavirus
A study in Japan has indicated that as of March, around 4.3 percent of the populations of Tokyo and four other prefectures had been infected with the coronavirus.
That's up from 2.5 percent in December.
The health ministry and the National Institute of Infectious Diseases have carried out surveys to estimate the proportions of people with coronavirus antibodies.
They conducted such a survey in December and another in February and March, when the country was gripped by the sixth wave of infections. The surveys covered a total of more than 16,000 individuals in Tokyo as well as Osaka, Miyagi, Aichi and Fukuoka prefectures.
Researchers calculated the proportions of people who had been infected with the virus based on ratios of those with infection-induced antibodies and others diagnosed with infection.
As of March, Tokyo had the highest ratio at 6.4 percent, followed by Osaka at 6.1 percent, Aichi at 3.7 percent, Fukuoka at 3.3 percent and Miyagi at 2.0 percent.
The ratio among those vaccinated against the virus at least once as of March was 4 percent, while that among those unvaccinated was 10 percent.
A similar analysis conducted by the US Centers for Disease Control and Prevention indicates that as of February, nearly 60 percent of the United States' population had been infected with the virus.
The head of the Japanese health ministry's expert panel, Wakita Takaji, said the infection rate in Japan has remained low to some extent.
But he cautioned that easing measures to reduce infection risks may allow the virus to spread more quickly, as the share of naturally infected people is small.