Analysis: Delta Variant Nearly Twice As Contagious
Researchers in Japan estimate that the Delta variant of the coronavirus now spreading in the country is 1.95 times more transmissible than the original virus. The variant was first identified in India.
A group led by Kyoto University Professor Nishiura Hiroshi and Hokkaido University Professor Ito Kimihito reported the results of their analysis at a meeting of an advisory panel to the health ministry on Wednesday.
The group examined the results of PCR tests in Tokyo, as well as an international coronavirus database.
The analysis shows that the variant is 1.95 times as contagious as the original virus, in terms of the average number of people a carrier will infect.
The researchers say that based on the data from Japan, the variant is projected to account for more than half of new cases by July 12.
They add that on July 23, when the Tokyo Olympics open, the variant is expected to account for 68.9 percent of daily new cases nationwide.
Nishiura says a recent increase in data on the variant allowed his group to conduct a more detailed analysis than before.
He warns that the variant's high transmissibility and the recent lifting of the coronavirus state of emergency in Tokyo and other urban areas will combine to raise the risk of infections in the near future.