Indian variant could become prominent

The Indian novel coronavirus variant also looks likely to have a major bearing on future infection figures in Japan, with some reports suggesting it could be 50% more contagious than the British variant.

“While it’s difficult to pinpoint when it might happen, it’s highly possible [the Indian variant] could overtake the British variant here,” National Institute of Infectious Diseases head Takaji Wakita said at a press conference on Wednesday.

According to the World Health Organization, the Indian variant started spreading rapidly in India in the latter half of March and has since been recorded in about 60 countries and territories around the world. A Health, Labor and Welfare Ministry tally showed that 160 people carrying this variant have been detected at airport quarantine checks in Japan, as have 29 people in seven prefectures. While some of these people have traveled overseas, officials have not been able to pinpoint the route of transmission, so tight border controls remain imperative.

The Indian variant has three types that all share the L452R spike mutation. Research has shown that hamsters infected with this new variant developed more severe inflammation of their lung tissue compared to those that received the original form of the virus. However, it remains unclear whether the Indian variant is more likely to cause severe symptoms in humans.

Vaccines appear to be effective against the British and Indian variants. In Britain, it was reported on May 22 that receiving two doses of the vaccine developed by U.S. pharmaceutical company Pfizer Inc. was 88% effective in stopping symptomatic disease from the Indian variant. Yokohama City University released research findings confirming that 97% of people who received two shots had developed antibodies for the Indian variant. Other data also has suggested vaccines are effective against this variant.

Much will hinge on whether the spread of this variant can be held in check until vaccines have been widely administered in Japan. From Friday, the government extended the period for which people returning from India and five other countries have to self-isolate at designated locations from six days to 10 days. The government also plans to start conducting PCR tests that can detect the Indian variant.

“Tighter border controls to detect the virus and follow-up on domestic cases will be important,” said University of Tokyo Associate Professor Kei Sato, a virology expert. “Steps to combat the virus, such as avoiding confined, crowded spaces, still need to be followed; so the key will be how we go about getting more people to actually adhere to these measures.” (May 30)