On Tuesday 26th May Japan’s COVID-19 state of emergency ended, five days earlier than expected and with deaths down to low double digits every day. The state of emergency was accompanied by a voluntary lockdown that started on 8th April for Tokyo and six other prefectures, extending to the rest of Japan a week later and ending in the rest of Japan a week before the lockdown ended in Tokyo. This means that the lockdown affected Tokyo for just 7.5 weeks, and the rest of Japan for about 6 weeks. At its peak the epidemic generated about 1200 cases in one day (on 17th April), dropping from 1200 to 30 in just 5 weeks.

In contrast, the UK essentially introduced its lockdown on 23rd March and is still slowly relaxing the lockdown. The UK lockdown was stricter than that in Japan, with enforceable restrictions on movement and activities[1], it involved the complete closure of many businesses, and it effectively lasted 3 weeks longer than Japan’s. At its peak the UK saw 8700 cases in one day (on 10th April, a week before Japan’s peak) and dropped much slower, only going below 2000 cases on 25th May – the same day Japan reached 30 cases. This is a quite remarkable difference in pace of decline: dropping by 97.5% in 5 weeks for Japan, compared to 75% in 6 weeks for the UK. These differences show very starkly when plotted, as I have done in Figure 1. This figure shows daily new cases in the two countries by day since the 10th confirmed case, using data obtained from the Johns Hopkins School of Public Health coronavirus tracker[2]. From this figure it is clear that Japan saw its 10th case much earlier than the UK (on 30th January compared to 24th February) yet experienced a much more gradual increase and a much more rapid decline than did the UK.

Figure 1: Daily new COVID-19 cases in the UK and Japan by day since the 10th confirmed case

Why was Japan’s response to the coronavirus so much more effective than that of so many other high-income countries? In this post I will explore a little the key factors that affected the Japanese response, what made the numbers grow so slowly and why the lockdown was more effective than in many other countries. In particular I will compare Japan with the UK, as a model of the differences between an effective and an ineffective response.

Figure 2: Health education materials are essential to good pandemic prevention

A timeline of interventions

Japan saw its first case on the 16th January, compared to 31st January in the UK. However, Japan took action sooner and more aggressively. Here are some key actions and when they were taken by each country.

The difference in public response to the issue of mass events is a key example of the quality of the response in the two countries. While the UK was faffing about with discussion about which responses to take, Japan was already canceling and closing events. My own work events began to be postponed in the last week of February, but so did major public events:

  • J league (soccer) halted all games on 25th February (170 cases)
  • Japan National Pro Baseball league held all preseason games without an audience from 26th February (189 cases)
  • Japan boxing commission and pro-boxing association canceled or postponed all bouts from 26th February
  • Rise kickboxing was canceled on 26th February
  • Sumo was held without an audience from 8th March (502 cases) (5 days after Boris Johnson bragged about “shaking hands with everybody” (51 cases))

In contrast in the UK:

  • An England-Wales Rugby match was held on 7th March with a live audience and the PM in attendance (206 cases)
  • Premier league events were held on 8th March with a live audience (283 cases)
  • Cheltenham races were held on 10th – 14th March (382 – 1140 cases)
  • League one games were held on 10th March (382 cases)
  • UEFA champions league games were held on 12th March (in Scotland) (456 cases)

The UEFA champions league match brought a large number of German fans to Scotland, and a week earlier I think Liverpool visited Spain and another team visited Italy, where the epidemic was already booming. These events had huge numbers of fans – 81,000 people attended the England-Wales rugby match, and many soccer games host tens of thousands of fans. In contrast, the only major event to be held in March in Japan that I know of, with an audience, was K1 on 22nd March, which attracted 6500 fans who were all given a mask at the door (and this event still attracted huge controversy and anger in Japan).

Because of the slow growth of the epidemic the lockdowns also happened at different stages of the epidemic. Japan’s lockdown came on 8th April, when there were 5120 cases; the UK’s, on the 23rd March, when the UK had reached 6600 cases and was already on a much more rapid upward trajectory. It took 4 days from the announcement of lockdown for the UK’s case load to double, whereas it took Japan 8 days. The next doubling took the UK another 4 days, and never happened for Japan.

Finally of course there is the attitude of the leadership: on 3rd March Sadiq Khan announced no risk of catching coronavirus on the London Underground, the same day that Boris Johnson was bragging about shaking everyone’s hand at a hospital (and thus caught coronavirus himself).

It should be clear from this that while in some cases the UK government acted with about the same speed as the Japanese government, in general the Japanese government acted when it had much lower numbers of cases than the UK, and implemented more far-reaching and aggressive strategies that were likely to have greater impact. But beyond basic actions on mass events and action plans, there was one additional major difference in the Japanese government’s response: case isolation.

Contact tracing and case isolation

From the very beginning of the epidemic, Japan introduced a system of “test, trace and isolate” that follows WHO guidelines for emerging infectious diseases. Under this system, once someone was identified as a likely COVID-19 case and tested positive, they were immediately moved to a nominated hospital into a special management ward designed for highly infectious diseases, to have their condition managed by specialist medical teams. This case isolation reduces the risk that they will infect their family, and prevents them from spreading the disease through basic daily functions like shopping if they live alone and cannot be helped by others. This strategy was also used in China and Vietnam, and it is a core part of the reason why the lockdowns in these countries were so much more effective than they were in the UK, USA or much of Europe. When a confirmed case of COVID-19 self-isolates at home they are highly likely to infect family or housemates, who will then continue to spread the virus amongst themselves and to others. This is particularly bad in cities with high levels of inequality like London, where essential workers live in cramped share houses and lack the resources to stop working even if infected. These people infect their housemates, who must continue working as bus drivers, cleaners, care workers or shop assistants, and cannot help but infect others. If the first case is quickly isolated, this reduces the risk that subsequent cases will be infected. As stressed by the WHO, case isolation is key to cracking this highly infectious virus. Case isolation early in the epidemic slows the growth of the epidemic and buys more time to scale up testing and other responses, while case isolation once the lockdown is in place helps to push down the number of infections more rapidly, reducing both the severity and length of the lockdown.

Case isolation was key to Japan’s successful management of this epidemic, but many people have suggested that the epidemic was controlled also because of cultural and social factors that make Japan more successful at managing infectious diseases. I do not think these played a major role in Japan’s response.

Japan’s “unique” social and cultural factors

Some have suggested that Japan’s culture of hygiene, its long-standing mask-wearing habits, and high quality public infrastructure might have played a role in slowing the growth of the epidemic. It is certainly true that Japanese people have a tradition of washing their hands when they get home (and gargling), wear masks when they are sick, and have remarkably clean and hygienic public spaces, with readily available public toilets throughout the country. The trains are super clean and stations are also very hygienic, and it is never difficult to find somewhere to wash your hands. Japanese people also don’t wear shoes in the house (and in some workplaces!) and often have a habit of changing out of “outside clothes” when they come home. But I think these cultural benefits need to be stacked against the many disadvantages of Japanese life: Japan’s trains are incredibly crowded, and everyone has to use them (unlike say California, which was much worse hit than Japan); Japanese shops and public accommodations in general are very cramped and crowded, so it is not possible to socially distance in e.g. supermarkets or public facilities; because Japan’s weather is generally awful and its insects are the worst things you have seen outside of anime specials, most of Japan’s restaurants and bars are highly enclosed and poorly ventilated; and Japanese homes are often very cramped and small. When viewed like this, Japan is a disease breeding facility, a veritable petri dish for a rapidly spreading and easily-transmissible disease. Japan’s population is also very much older than the UK’s, which should suggest further high rates of transmission, and from mid-February we have terrible hay fever which turns half the country into snot cannons. Not to mention the huge outdoor party that is held at the end of March, where everyone gets drunk and nobody socially distances. Japan’s work culture also does not support home working, in general, and everyone has to stamp documents by the hour and we still use fax machines, so I really don’t think that this is a strong environment to resist the disease. I think these social and cultural factors balance out to nothing in the end.

Differences in Personal Protective Equipment

I do not know what the general situation for PPE was in Japan, but certainly the hospital attached to my university, which is a major nominated infectious disease university, sent around a circular in mid-February describing our state of readiness, and at that time we had 230 days’ supply of COVID-rated gowns at the current infection rate, as well as ample stocks of all other PPE and plans in place to secure more. There was a shortage of masks for public use in March, which was over by April, but I do not get the impression that there was such a shortage in the designated hospitals. Japan also has a very large number of hospital beds per capita compared to other high-income countries, but this figure is misleading: most of these beds are for elderly care and not ICU, and in fact its ICU capacity is not particularly large. However, by keeping the new cases low and moving isolated patients to hotels once the hospitals became full, Japan managed to mostly avoid shortages of ICU beds (though it was touch and go for a week or two in Tokyo). I think in the Japanese hospital system the lack of ventilators and ICU beds would have become a major problem long before the country ran out of PPE.

Inequality and disease transmission

One way that Japan differs from a lot of other high-income countries is its relatively low levels of inequality. In particular it is possible for young people to live alone in Tokyo even if they do not have high incomes, which means share housing does not really exist here, and all the young people who move to the big cities for work mostly live by themselves where they cannot infect anyone. Although it is a very densely-populated country and houses are much smaller than in the UK, there is less overcrowding because housing is affordable and there is a lot of it. Most people can afford health care and have ready access to it (waiting times are not a thing here). This low inequality plays an important role in elderly care homes, where staff are better paid and treated than in the UK care sector, and less likely to move between facilities on zero-hour contracts as they do in the UK. There is a higher level of care paid to basic public facilities like hospitals, railway stations, public toilets and other facilities which ensures they are relatively hygienic, and cleaning staff here tend to be paid as part of a standard company structure rather than through zero-hours contracts, with good equipment and basic working rights. Also there is a much lower level of obesity here, and obesity is not as class-based, so there is less risk of transmission and serious illness through this risk factor. There is a very high level of smoking, which is a major risk factor for serious illness and death from COVID-19, but it is the only risk factor that is comparable to or higher than those in the UK. In general I think Japan’s low level of inequality helped in the battle against this disease, by preventing the country from developing communities where the disease would spread like wildfire, or having strata of the population (like young renters) at increased risk, or forcing increased risk onto the poor elderly as we saw in the UK.

A note on masks

I think masks are a distraction in the battle against this disease. I think most people don’t know how to wear them properly and use them in risky ways – touching them a lot, reusing them, wearing them too long, storing them unsafely, and generally treating them as part of their face rather than a protective barrier. I think that this can create a false sense of security which leads people to think that opening up the economy and dropping lockdown can be safely done because everyone is protected by masks. This is a dangerous mistake. That is not to say one shouldn’t wear them, but one should not see them as a solution to the more basic responsibility of social distancing and isolation, and one definitely should not drop one’s hand hygiene just because one is wearing a mask: hand hygiene is much more important for protecting against this disease. It’s worth remembering that on the days that Japan was seeing 300 or 500 or 1000 cases a day everyone was wearing masks, but somehow the disease was still spreading. They are not a panacaea, and if treated as an alternative to really effective social measures they may even be dangerously misleading.

Conclusion: Early, sensible action and strong case isolation are the key

Japan took an early, rapid response to the virus which saw it screening people at airports, educating the population, and implementing sensible measures early on in the epidemic to prevent the spread of the disease. The first measures at airports and in case isolation were taken early in February, major events were cancelled and gatherings suspended from mid- to late-February, and additional social distancing measures introduced in March. Throughout the growth of the epidemic the Japanese response focused on the WHO guideline of testing, tracing, and isolating, with case isolation a routine strategy when cases were confirmed. This case isolation slowed the growth of the epidemic and once lockdown was in place helped to crush it quickly. This in clear contrast to the countries experiencing a larger epidemic, which typically reacted slowly, introduced weak measures, and did not implement case isolation at all or until it was too late. Lockdowns with self-isolation will work, but as Figure 1 shows, they are much less effective, causing more economic damage and much slower epidemic decline, than lockdowns with case isolation.

Finally I should say I think Japan ended its lockdown a week early, when cases in Tokyo were still in the 10s, and we should have waited another week. I fear we will see a resurgence over the next month, and another lockdown required by summer if our contact tracing is not perfect. But it is much better to end your lockdown prematurely on 10 cases a day than on 2000 a day, which is where the UK is now!

fn1: With certain notably rare exceptions, of course…

fn2: I have had to do a little cleaning with the data, which contains some errors, and I think the JHSPH data doesn’t quite match that of national health bodies, but it is much more easily accessible, so that is the data I have used here. All case numbers are taken from that dataset, unless otherwise stated.