Current Situation of Infection, January 6, 2022

66th meeting of the COVID-19 advisory board of Ministry of Health, Labour and Welfare (January 6, 2022). Material 1

Evaluation of the latest infection status, etc.

Infection status

The number of newly infected people is increasing rapidly. The number of new cases of infection (by date of report) nationwide was about 5 per 100,000 in the last week, and the most recent week-to-week ratio was 3.26. Among the areas where the number of infected people has been increasing rapidly, it was approximately 80 per 100,000 in Okinawa, with a week-to-week ratio of 6.95, approximately 22 per 100,000 in Yamaguchi, with a week-to-week ratio of 11.11, and approximately 14 per 100,000 in Hiroshima, with a week-to-week ratio of 24.69. In addition, the number of new cases of infection has increased mainly in urban areas such as the Kanto and Kansai regions. With the rapid increase in the number of new cases of infection nationwide, the number of patients being treated and the number of severe patients are on the rise.
The number of cases of infection with the Omicron variant is continuously increasing overseas. In Japan, infection with the Omicron variant has been confirmed in about 80% of prefectures, and there are some regions where cases of unknown infection route and no history of overseas travel continue to occur. Considering that there are some regions where the Delta variant is being replaced, it is necessary to be aware that the spread of infection might rapidly progress and the medical care provision system may become strained.
Effective reproduction number:On a national basis, the most recent number remains above 1 at 1.31 (as of December 21). The figure is 1.26 in the Tokyo metropolitan area and 1.35 in the Kansai area.

Future outlook and measures to be taken

There is a strong possibility that infection will rapidly increase in the future. The number of new cases of infection nationwide increased rapidly from the end of the year to the beginning of the year, and the number of cases infected with the Omicron variant has also been increasing. Particularly in Osaka and Okinawa, among the cases of infection with the Omicron variant, cases unrelated to overseas travel continue to occur, and the Delta variant is already being replaced by the Omicron variant. In addition, although the nighttime population is below the level at the end of last year in a wide range of regions, the current increase in the number of infected cases still reflects the situation around Christmas. In addition to the increase in movement and contact of people due to returning home at the end and the beginning of the year, considering the 3-day weekend, coming-of-age ceremonies and related gatherings, and increased indoor activities as the temperature further decreases, there is a risk that the infection will spread further.
Depending on the future increasing trend, there are concerns about strains on the medical care provision system and the spread of infection to people at high risk of becoming severely ill. Preliminary reports on the properties and epidemiological evaluation of the Omicron variant have been made by international organizations and other countries. Information is also being obtained from domestic cases of infection. Although information is currently limited, the epidemic strain is rapidly being replaced from the Delta variant to the Omicron variant in South Africa, the United Kingdom, etc., and there is concern about high transmissibility. Compared to the Delta variant, it has been pointed out that the Omicron variant has shortened generation time, doubling time and incubation period, and the risk of secondary infection and reinfection is increased. It has been reported that although the vaccines’ preventive effect against disease aggravation has been maintained at a certain level, the preventive effect on disease onset is markedly reduced. Laboratory evaluations have indicated that some antibody therapeutics may be less effective. Epidemiological information and laboratory studies that the Omicron variant may be less likely to become severe than the Delta variant. However, if the number of infected cases rapidly increases due to the rapid spread of infection, the number of patients requiring treatment at home, accommodation facilities for recuperation or hospitalization may rapidly increase, and the medical care provision system for mild and moderate cases may quickly become strained. If infection spreads rapidly among people at high risk of aggravation, the incidence of severe illness or death may increase.
Preventative and agile efforts are required at borders and each site in Japan.
- As measures against the Omicron variant at border control, it is necessary to regard those who are positive in the immigration inspection as positive for the Omicron variant, to promptly identify and respond to close contacts on the airplane, and continue whole-genome analysis for positives.
- In Japan, there is a concern about rapid spread of infection by the Omicron variant, and it is necessary to continue the surveillance system. Infection with the Omicron variant has been confirmed in Japan, and early detection by thorough implementation of the testing system, prompt and active epidemiological investigation, and implementation of measures to prevent spread of infection are necessary. It is recommended that those who have shared the same space as the cases with Omicron variant infection should undergo a wide range of tests, regardless of whether they wore a mask or the duration of contact.
- Based on the infection status of the region and forecasts of the numbers of infected cases and severe cases, local governments must flexibly work to secure the required number of beds, secure support for strengthening the healthcare center system such as tests and epidemiological surveys, and establish home-visit and online medical care systems for home care recipients.
Immediate review of the business continuity plan of each facility in the region is needed.

Due to the rapid spread of infection in the region, infection of employees and their families or withdrawal from the workplace due to close contact is highly likely, especially in medical institutions and nursing welfare facilities. The same thing can happen at all workplaces involved in maintaining social functions, such as local governments including healthcare centers and transportation facilities. This is a business continuity plan review to prepare for such a situation. The use of telework is also required in the workplace.
The provision of information to unvaccinated people and those receiving booster vaccination must be reinforced.

Amid concerns about the rapid spread of the Omicron variant, it is especially necessary to promote vaccination of unvaccinated people, and local governments must enhance the communication of information to those who still have to be vaccinated. At the same time, the booster vaccination that started in December last year must also be steadily implemented. In doing so, it is necessary to smoothly carry out the acceleration of the schedule for healthcare professionals and the elderly at high risk of becoming severely ill. In addition, since specially approved oral medications can be used in patients at high risk of mild to moderate aggravation, they are expected to improve access to treatment and have a certain preventive effect on aggravation.
It is necessary to widely share the assumption of rapid spread of infection by the Omicron variant.
- Government, businesses and citizens need to act with the recognition that the replacement of the Delta variant with the Omicron variant in Japan is progressing, and that rapid spread of infection should be assumed.
- Basic anti-infection measures are also important for the Omicron variant, and it is necessary to continue to ensure proper wearing of masks, hand washing, ventilation, etc., including among vaccinated people. Although the risk of infection is highest when the three Cs (crowded places, closed spaces, and close contact) overlap, even one C should be avoided as much as possible due to the high transmissibility of the Omicron variant.
- It is well known that in regions where infection with the Omicron variant has been confirmed, free tests are available for those who are concerned about infection and wish to have such a test.
The cooperation of citizens and businesses is crucial to prevent the spread of infection.

In celebrating the New Year, at annual events such as New Year's parties and coming-of-age ceremonies, when eating and drinking out, it is necessary to select a third part-certified restaurant having good ventilation, with as few people as possible, avoiding loud noises and long hours, and wearing a mask when not eating or drinking. Crowded places and places with a high risk of infection must be avoided when going out. In order to protect your own life and at the same time to prevent the spread of infection by the Omicron variant, it is recommended to refrain from going out if you feel a little unwell, such as mild fever or fatigue, and to proactively be examined and receive tests. Particularly in areas where the rapid spread of infection is causing concern about strain on the medical care provision system, more careful judgment and action are required.

Figures (Number of new infections reported etc.) (PDF)