TOKYO: The British variant of the coronavirus that causes COVID-19 is 1.32 times more infectious than the original virus, a Japanese study has found.

The study by Japan’s National Institute of Infectious Diseases, which covered 803 cases of the British variant, compares with overseas studies that found the variant’s infectivity is 43 percent to 90 percent higher than the original’s.

According to the Japanese institute, the variant’s effective reproduction number, or the average number of infections from a carrier of the variant, came to 1.23 for a period between February and late March, against the original’s 0.94.

Given the possibility of initial failure to identify the British variant in some coronavirus cases, the variant’s reproduction number may have actually been higher than the Japanese study showed.

The institute warned that in light of the British variant’s strong infectivity, existing measures may not be enough to contain the pandemic.

The institute also found that the share of people under 18 among carriers of the British variant is larger than their share among carriers of the original virus.

Children aged at 5 or younger accounted for 4.3 percent of the surveyed British variant cases, against 2.1 percent of the surveyed original-virus cases.

The proportion of those aged between 6 and 17 stood at 10.3 pct among the variant cases, against 5.7 percent among the original-virus cases.

JIJI Press