Photo/Illutration

The highly contagious BA.5 Omicron subvariant and the July 10 Upper House election are partly responsible for a recent unprecedented spike in COVID-19 cases in Japan, according to an expert.

The country topped the list of nations with a high number of new cases in the week from July 18 to 24, the World Health Organization (WHO) announced on July 27.

Japan also stands out for the number of new infections per 1 million people.

The nation had about 10,000 new cases per 1 million people over the week through July 27, an Asahi Shimbun analysis of WHO data showed.

The figure remained mostly low in other countries. Per 1 million people, there were roughly 7,000 cases in France and Germany, around 2,500 in the United States and about 2,000 in Britain, which covers the week through July 21.

However, a simple comparison is impossible since little information is available on each country’s testing status.

The actual number of cases in Japan is believed to be higher than reported as infections are rising so sharply that not everyone can be tested even if they want to. It is also unclear how much other nations have been able to detect positive cases through testing.

Britain and other Western nations stopped rigorously conducting PCR tests, said Yoshiaki Katsuda, a professor of travel medicine at Kansai University of Social Welfare, who is well-versed in infectious diseases.

Japan is currently the world leader in the number of weekly new cases, but the figures for the United States and European countries used to be much higher.

Weekly new cases per 1 million people in January topped 35,000 in France, 20,000 in Britain and 15,000 in the United States, another Asahi Shimbun analysis of WHO data showed.

New infections are rising at an unprecedented pace in Japan, which is unlikely to subside anytime soon. The situation is putting a greater strain on the health care system.

The BA.5 subvariant began spreading at the end of May in Japan, Katsuda said, where fewer people had acquired immunity against the novel coronavirus through infections than other countries.

He believes an increase in people’s activities ahead of the Upper House election also helped fuel the current seventh wave of infections, he said.

New cases will likely start declining in August as the recent spike in infections is expected to temporarily drive up the number of people with immunity, according to an estimate presented at a July 27 meeting of the health ministry’s advisory panel of experts on the pandemic.

But concerns were raised that another Omicron subvariant called BA.2.75 could become the dominant strain in Japan.

Some experts said the subvariant appears to be more transmissible since it has eight more mutations on the spike protein than the BA.2 Omicron subvariant, which raged in Japan this past winter.

The spike protein, which sticks out from the surface of the virus and infects human cells, largely determines the infectivity of the virus, impacting the effectiveness of COVID-19 drugs and vaccines.

Katsuda expressed concerns about a possible simultaneous outbreak of the novel coronavirus and the flu or other infectious diseases.

He said people should avoid settings with a high-infection risk and receive booster shots to prevent elderly people from contracting the novel coronavirus and becoming seriously ill.

That will also help prevent the health care system from being overwhelmed with serious cases, said Katsuda.

The Japanese government maintains that it will not impose anti-virus measures to restrict people’s movements to curb the current wave of infections.

But health care workers are urging the government to change that policy as some medical institutions have become unable to provide services due to infected staff members being absent from work.

(This article was written by Yoshinori Hayashi and Kenta Noguchi.)

Related News