The government will test around 10,000 people for coronavirus antibodies starting next month to gauge how far the contagion has spread and whether the nation is approaching “herd immunity,” the health minister said Friday.
The tests, which determine whether someone has had contact with COVID-19, will be conducted in specific areas rather than nationwide, Health, Labor and Welfare Minister Katsunobu Kato told a news conference.
The results are expected to help grasp the extent of the virus’s spread in the targeted regions and whether Japan is on its way to herd immunity, where a large portion of the population develops enough antibodies to limit the spread of the virus.
The tests use a blood sample and take less time than the polymerase chain reaction test, which uses a sample from a patient’s nose and requires several hours to produce a result.
In late April, the ministry conducted a testing trial based on blood samples donated in Tokyo and six prefectures in Tohoku, using test kits from five companies and found that three, or 0.6 percent, of 500 samples from Tokyo and two, or 0.4 percent, of 500 samples from Tohoku tested positive. But experts said it is inappropriate to discuss antibody ratio based on such a small number of samples, according to the ministry.