Scientist behind Japan’s successful Covid model now battles new surge as winter sets in

Hitoshi Oshitani’s 'Three C’s' approach — avoiding closed spaces, crowded places and close contact situations — had helped Japan avoid thousands of deaths without lockdown.

File Image of Japan's leading virology expert Hitoshi Oshitani |Bloomberg

Having mocked him at first for his theories on how the coronavirus spread, the world came to recognize the effectiveness of Japanese scientist Hitoshi Oshitani’s “Three C’s” approach to the pandemic: avoiding closed spaces, crowded places and close contact situations where the virus thrives.

It’s a strategy that’s helped Japan avoid thousands of deaths without a lockdown — but one that’s now being challenged with infections rapidly escalating as cold weather sets in. Oshitani fears the nation may not be ready.

“People’s concern is decreasing,” Oshitani, a virologist and infectious disease specialist, said in an interview with Bloomberg News. “We may see a sudden increase in severe cases and deaths.”

Oshitani has become a global ambassador of the “Japan Model” thanks to his prescient insight into how the virus was transmitted. While most public health experts focused on hand-washing and surface transmission, and other countries debated over wearing masks, as early as March Oshitani concentrated on tracking down clusters of infections and ensuring people avoid the Three C’s.

As a result, the virus toll in Japan has been a fraction of that in the U.S. and many European countries, even as life largely returned to normal. Japan has recorded around 124,000 cases in total and the country, which has the oldest population in the world, has faced fewer than 2,000 deaths.

Now the nation finds itself faced with a resurgent and growing outbreak, with cases hitting another record on Thursday and the capital Tokyo posting its highest-ever numbers two days in a row. Local officials around the country have begun eyeing stricter measures to limit business hours, though authorities are limited in the steps they can take as the constitution doesn’t provide the legal power to enforce lockdown restrictions.

But Oshitani worries it’s becoming harder to influence behavior compared to the spring, when the unknown menace of the pandemic forced people to change their own habits. While many countries are struggling with lockdown fatigue, Japan’s position is unusually perilous — without the ability to enforce restrictions, it’s dependent on people’s cooperation with voluntary measures.

“I don’t think this virus will go away in the coming months, and probably the coming years, so we have to find the best way to live with this,” he said. “And that’s what we are still struggling with — to find the best way.”

Early realization

From the very start, Oshitani took the approach that the new coronavirus was one that couldn’t be eliminated, only controlled. This was in contrast to the SARS outbreak, which he coordinated the Asian response against while working at the Western Pacific office of the World Health Organization.

“In the very beginning, he said there was no way to crush this virus — rather, humanity had to rethink their current way of living from the very core,” said Kaori Muto, a professor at the University of Tokyo, who worked with Oshitani on a group advising the government.

By analyzing preliminary data from Japan’s health centers and the Diamond Princess cruise ship as well as through discussion with his WHO contacts, Oshitani quickly narrowed in on the possible transmission tendencies of the new coronavirus, working together with Hiroshi Nishiura, an expert in mathematical modeling of infectious diseases currently at Kyoto University.

Oshitani also relied on intuition developed through his past work — remembering a research meeting at the WHO documenting that influenza, typically transmitted via droplets and contact, could be airborne for short distances. That led him to hypothesize the same might apply for the virus that had just emerged from Wuhan.

Months ahead of peers, Oshitani and Nishiura realized the virus would spread most easily in poorly ventilated indoor environments, and designed the Three C’s strategy to tackle this source of transmission. The WHO didn’t acknowledge airborne transmission until July.

Most infected people wouldn’t transmit the coronavirus to others, the Japanese scientists observed, while unlike influenza, a small group of super-spreaders could be responsible for huge numbers of infections. Instead of rushing to ramp up testing and identify every person infected as officials did in other countries, Japanese authorities focused instead on breaking up clusters of the disease. And they noted how the virus could spread among carriers free of symptoms, likely not to even know they were infectious.

While many of those ideas are now commonplace among public health officials, they weren’t generally accepted at the time.

“Most people believed that it’s spreading like influenza, and Oshitani’s theories were just his imagination — or his delusion,” said Tomoya Saito, director of the Department of Health Crisis Management at the National Institute of Public Health.

SARS experience

While the outlier response meant Japan’s initial success was met with bemusement, skepticism or treated as a mystery, Oshitani has since become a regular speaker on the public health circuit. Last week, he addressed more than 200 U.S. state and local officials at a Harvard University webinar to share data on Japan’s contact tracing methods, and almost every day takes interviews from media across the world.

“It’s because of his efforts and the way he presents his data that we understand so much about what can be done in the Covid situation today,” said David Heymann, a professor of infectious disease epidemiology at the London School of Hygiene & Tropical Medicine who has worked with the WHO for decades.

Oshitani, an unassuming and bespectacled 61-year-old, is at times hardly distinguishable from the average salaryman. A field epidemiologist by training, Oshitani cut his teeth working for Japan’s development agency in Zambia, and has spent most of his career as an academic, currently affiliated with Tohoku University. He’s far less well-known in his native country than other top infectious disease officials like Anthony Fauci in the U.S., and unlike Sweden’s Anders Tegnell, no one is tattooing his image on their bodies.

But those who worked with Oshitani say his early sense of urgency, constantly badgering government officials to do more, was crucial to Japan’s response.

Oshitani remains an iconoclast in some of his thinking. He’s not worried about finding every individual case of the virus in Japan — he’s criticized Western nations for their mass-testing approach, arguing it makes contact-tracing impossible. It’s likely, he says, that Japan’s case count only reflects a third to half of the real infection numbers, and might even be closer to 1 million.

Oshitani’s true fear is missing a cluster of infections that could trigger an uncontrollable spread of the virus in Japan, one that would hit the nearly one-third of the country’s population that is over the age of 65, and overwhelm the health system. That’s becoming more plausible as clusters pop up in multiple areas across Japan, threatening to stretch his model to breaking point.

And should that happen, with authorities severely limited in how much they can compel cooperation, Japan has to hope that its residents can snap out of pandemic fatigue, and that voluntary compliance can bring things under control again.

“The number of cases can jump anytime within one or two weeks,” Oshitani said. “If we wait until the number of cases reach a certain point, it may be too late.”-Bloomberg