Contrary to some expertsâ€™ warnings that the coronavirus sixth wave feared to hit Japan this winter could surpass the scale of the summerâ€™s fifth wave, which saw a sharp increase in COVID-19 patients and pressure on the medical system, artificial intelligence (AI) has recently produced interesting predictions that Tokyo might record 370 new cases daily at the sixth waveâ€™s peak, about the same as spring 2020â€²s first wave.
Daily new infections have stayed low in Japan of late, but can infections be brought under control without another outbreak?
Japanâ€™s nationwide daily COVID-19 counts, which exceeded 25,000 at one point during the fifth wave, were down to just 77 on November 24 a 99 percent decrease. On that day, Tokyo recorded five cases, the lowest this year.
But experts are wary the sixth wave will be worse than the fifth. The central government is also assuming it will have double the infectivity of the delta-fueled fifth wave. Sixth wave preparations include creating a system by the end of November that can ensure 37,000 patients, 30 percent more than in the fifth wave, can be hospitalised.
Amid this, predictions by an AI developed by Professor Akimasa Hirataâ€™s team at Nagoya Institute of Technology are attracting attention. To make the estimate, the team made the AI memorise vaccine efficacy, past outbreaksâ€™ cycles, the schedule of major vacations in Japan and other factors.
For Tokyo, the AI predicted that new daily infection cases would continue to be 50 or less for the rest of the year, with increases starting around the end of 2021 due to end of the year parties and people returning to their hometowns. Even so, it estimated the peak would be 370 in mid-January 2022.
â€œIt is a prerequisite that we continue measures against infection, such as wearing masks, but vaccinationsâ€™ impact is significant. Not just in Tokyo but also on a nationwide scale, the sixth wave this winter will be suppressed to one-fifth to one-tenth of the fifth wave,â€ Hirata said.
Third round vaccinations beginning in December are considered key to controlling infections. Without booster shots, the AI predicts that a decline in vaccine effectiveness will mean April 2022 sees infections on a scale equivalent to the fifth wave.
Hirata said, â€œIf the third round of vaccination starts December 1 as scheduled, we may be able to prevent infections spreading without reducing human activity too much. But it is important to keep taking countermeasures against infections. Drugs (to treat COVID-19) are also gradually available, so if we can get through this winter, we may be a step closer to ending the pandemic.â€
In fact, the AI has successfully predicted the new casesâ€™ rapid decline since this summerâ€™s fifth wave, when daily counts in Tokyo exceeded 5,000. During the infections peak on August 12, Shigeru Omi, head of the governmentâ€™s coronavirus countermeasures subcommittee, asked the public to â€œreduce movement by 50%â€ to control infections.
But at the time, Hirata indicated that even without reducing movement, daily COVID-19 cases would decrease rapidly after September 10, and that by around October 6, Tokyoâ€™s new cases would be down to 210. In the end, October 6 recorded 149 infections.
Looking at the world, however, the pandemic canâ€™t be said to be ending. A World Health Organization report released November 14 showed there were about 3.3 million new infections per week, up on the previous seven days. About 50,000 deaths a week were reported.
In the November 14 report, the US had the most new weekly cases per country with 550,684, up 8 percent from the previous week. It was followed by Russia with 275,579 (about the same as the previous week), Germany with 254,436 (up 50 percent from the previous week), the UK with 252,905 (about the same as the previous week), and Turkey with 180,167 (down 9 percent from the previous week).
Atsuo Hamada, a specially appointed professor at Tokyo Medical University and an infectious diseases expert, said, â€œCountries experiencing increases may be doing so due to winterâ€™s arrival. It is believed the coronavirus spreads more in winter.â€
Although the AI predicts a relatively small outbreak, Hamada stressed: â€œWe should be prepared for a sixth wave in Japan, too.â€