While many countries are fighting off their worst coronavirus outbreaks yet, Japan is detecting hardly any COVID-19 infections at all. Observers are trying to figure out why.
As recently as late summer, Japan’s coronavirus outlook wasn’t great. An outbreak coinciding with the Tokyo Olympics was killing dozens per day and overwhelming hospitals.
Starting in September, though, as Japan ramped up its vaccination campaign, the country saw a dramatic plunge in the number of reported cases and eventually the number of deaths.
Since then, the situation has only improved. Japan this month has reported an average of less than one COVID-19 death per day – a shockingly low number for a country of 126 million.
No one knows exactly why Japan has experienced such success -- especially while other countries, even its immediate neighbors, have been hit by serious winter waves of the coronavirus.
There are many possible explanations. Nearly 80% of Japan’s population is fully vaccinated. Virtually everyone wears masks. Even after the government relaxed restrictions this autumn, people continued to socially distance themselves.
Some researchers have pointed to Japan’s low rates of obesity. Several recent studies have concluded that COVID-19 is more severe in obese individuals.
Cultural customs may also play a role. For instance, the Japanese do not typically kiss, hug, or even shake hands during greetings. Many Japanese are also relatively quiet in public settings, points out Kentaro Iwata, an infectious disease specialist at Japan’s Kobe University.
“Masking and keeping silent in public places is very important [for fighting the virus]. Everybody knows it, but practicing it can be very difficult in some parts of the world, maybe due to cultural reasons,” said Iwata, who has dealt with infectious outbreaks for more than 20 years, by email.
Those factors, however, do not explain why neighboring South Korea, which shares many cultural traits, is dealing with its worst COVID-19 outbreak yet.
One possible explanation is that Japan is testing far fewer people, Kenji Shibuya, an epidemiologist and researcher at the Tokyo Foundation for Policy Research, said.
In the first half of December, Japan tested an average of 44,623 people per day, according to government data. South Korea, whose population is less than half that of Japan, conducted an average of 238,901 tests per day during the same period, according to official data.
Because of Japan’s lack of testing, it is difficult to believe that official case figures reflect the reality on the ground, Shibuya told VOA in an email.
If the lack of testing were a major factor, though, Japan would have likely seen a surge in other indicators, such as the number of hospitalizations or deaths from respiratory illnesses, as other experts have noted.
In the absence of any definitive explanation, some researchers have tried to identify a so-called X-factor. One study even suggested many Japanese people share a genetic feature linked to white blood cells that helps the fight against COVID-19. Others theorize that the coronavirus variant spreading in Japan may have mutated itself into extinction.
Whatever the reason for Japan’s success, the battle is not over, said Shibuya, who said he still expects the country to see a winter wave of infections.
In a possibly ominous sign, Japan this week identified its first cases of community transmission of the omicron variant, which scientists say spreads much faster than previous iterations of the virus. Many of those found to be infected with omicron had no history of overseas travel, officials said.