70th meeting of the COVID-19 advisory board of Ministry of Health, Labour and Welfare (February 2, 2022).  Material 1

Evaluation of the latest infection status, etc.

Infection status

• The number of new cases of infection (by date of report) nationwide increased continuously to approximately 426 per 100,000 in the latest week. However, at the same time, its ratio to that for the previous week is 1.5, indicating a continuous downward trend, with an increasing pace. The number of new cases of infection has increased mainly, in people in their 20s or younger. Seen by age group, the proportion of patients in their 20s has decreased, while the proportion of patients under 10 years old has increased.
• Among the 34 prefectures that are currently under priority preventative measures, 31 prefectures (other than Okinawa, Shimane, and Hiroshima) are continuing to show an increase. Nearly all prefectures that are under priority measures have a ratio of new cases for this week to that for the previous week of 2 or lower; however, some areas continue to show a rapid increase, with a ratio of more than 2. On the other hand, Okinawa continues to show a decrease, with a ratio of new cases for this week to that for the previous week of less than 1. However, it should be noted that although the number of new cases of infection is decreasing in young people, mainly in those in their 20s, it is increasing in elderly people in their 70s.
• In 13 prefectures where priority measures are not in force, some areas continue to show a rapid increase in the number of new cases of infection, with a ratio to that for the previous week of more than 2.
• With the continued increase in the number of new cases of infection nationwide, both a rapid increase in the number of patients receiving treatment and an increase in the number of severe patients continue to be seen.
• Although the Delta variant is still being detected, it has nearly been replaced by the Omicron variant in the Tokyo metropolitan area and the Kansai area.

  Effective reproduction number: On a national basis, the most recent number is above 1 (1.19; as of January 17), and the figure stands at 1.23 in the Tokyo metropolitan area and 1.19 in the Kansai area.

Local trends

* The value for new cases of infection is the number of persons per 100,000 among the total number for the latest week, based on reporting dates.

< Area subject to priority measures >

1. Hokkaido

   The number of new cases of infection has increased continuously to approximately 353 (approximately 505 in Sapporo City), with a ratio to that for the previous week of 1.7. The infected individuals are mainly in their 30s or younger. The use rate of beds is slightly less than 30%.

2. Tohoku

   In Aomori, the number of new cases of infection has increased continuously to approximately 186, with a ratio to that for the previous week of 1.7. The infected individuals are mainly in their 20s or younger. The use rate of beds is slightly more than 20%. In Yamagata and Fukushima, the number of new cases of infection has also increased continuously, to approximately 132 and 152, respectively. Both prefectures show a rapid increase, with a ratio to that for the previous week of more than 2. The use rate of beds is slightly more than 20% in Yamagata and slightly more than 40% in Fukushima.

3. North Kanto

   In Gunma, the number of new cases of infection has increased continuously to approximately 349, with a ratio to that for the previous week of 1.5. The infected individuals are mainly in their 30s or younger. The use rate of beds is slightly more than 50%. In Ibaraki and Tochigi, the number of new cases of infection has also increased continuously, to approximately 222 and 230, respectively. Both prefectures show an increase, with a ratio to that for the previous week of more than 1. The use rate of beds is slightly more than 30% in both prefectures.

4. Metropolitan area (Tokyo and 3 neignboring prefectures)

   Tokyo continues to show a rapid increase in the number of new cases of infection. The number has reached the highest value in Japan (approximately 767), with a ratio to that for the previous week of 1.6. The infected individuals are mainly in their 20s and 30s, while the number of those aged less than 10 years are also increasing. The use rate of beds is slightly less than 50%, while the use rate of beds for severe patients is slightly more than 30%. In Saitama, Chiba, and Kanagawa, the number of new cases of infection has also increased continuously, to approximately 399, 392, and 504, respectively. Both prefectures show an increase, with a ratio to that for the previous week of more than 1. The use rate of beds is slightly less than 60% in Saitama, and slightly less than 50% in Chiba and Kanagawa.

5. Chubu/Hokuriku

   In Ishikawa, the number of new cases of infection has increased continuously to approximately 248, with a ratio to that for the previous week of 1.7. The infected individuals are mainly in their 20s or younger. The use rate of beds is slightly more than 40%. In Niigata and Nagano, the number of new cases of infection has also increased continuously, to approximately 152 and 189, respectively. Both prefectures show an increase, with a ratio to that for the previous week of more than 1. The use rate of beds is slightly more than 20% in Niigata and slightly more than 60% in Nagano.

6. Chukyo/Tokai

   In Aichi, the number of new cases of infection has increased continuously to approximately 462, with a ratio to that for the previous week of 1.6. The infected individuals are mainly in their 30s or younger. The use rate of beds is slightly more than 50%. In Gifu, Shizuoka, and Mie, the number of new cases of infection has also increased continuously, to approximately 273, 276, and 231, respectively. Both prefectures show an increase, with a ratio to that for the previous week of more than 1. The use rate of beds is slightly more than 60% in Gifu, slightly more than 30% in Shizuoka, and slightly more than 40% in Mie.

7. Kansai area

   In Osaka, the number of new cases of infection has increased continuously to approximately 760, with a ratio to that for the previous week of 1.5. The infected individuals are mainly in their 30s or younger. The use rate of beds is slightly more than 70%, while the use rate of beds for severe patients is slightly more than 30%. In Kyoto and Hyogo, the number of new cases of infection has also increased continuously, to approximately 600 and 549, respectively. Both prefectures show an increase, with a ratio to that for the previous week of more than 1. The use rate of beds is slightly more than 50% in Kyoto and slightly more than 60% in Hyogo. The use rate of beds for severe patients is approximately 40% in Kyoto.

8. Chugoku/Shikoku

   In Hiroshima, the number of new cases of infection is approximately 328, with a ratio to that for the previous week of less than 1 (0.98). The infected individuals are mainly in their 30s or younger. The use rate of beds is approximately 50%, while the use rate of beds for severe patients is slightly more than 20%. In Okayama, Yamaguchi, and Kagawa, the number of new cases of infection has also increased continuously, to approximately 320, 190, and 241, respectively. In Shimane, the number of new cases of infection has decreased to approximately 87, with a ratio to that for the previous week of less than 1 (0.5). In Okayama, Yamaguchi, and Kagawa, the number of new cases is continuing to increase, with a ratio to that for the previous week of more than 1. The use rate of beds is slightly more than 30% in Shimane, slightly more than 40% in Okayama, approximately 50% in Yamaguchi, and slightly more than 30% in Kagawa.

9. Kyushu

   In Fukuoka, the number of new cases of infection has increased continuously to approximately 548, with a ratio to that for the previous week of 1.6. The infected individuals are mainly in their 30s or younger. The use rate of beds is slightly less than 50%. In Saga, Nagasaki, Kumamoto, Oita, Miyazaki, and Kagoshima, the number of new cases of infection has increased continuously, to approximately 362, 302, 406, 247, 247, and 248, respectively. Both prefectures show an increase, with a ratio to that for the previous week of more than 1. The use rate of beds is approximately 40% in Saga, slightly less than 40% in Nagasaki and Miyazaki, slightly more than 70% in Kumamoto, slightly more than 40% in Oita, and slightly more than 50% in Kagoshima.

10. Okinawa

    The number of new cases of infection is approximately 439, and the ratio to that for the previous week remains less than 1 (0.8). In the Yaeyama district, the increase is continuing. The newly infected individuals are mainly in their 30s or younger, while the number of those in their 70s is increasing. The use rate of beds is slightly less than 70%, while the use rate of beds for severe patients is approximately 60%.

< Areas other than the above >

In Iwate, Miyagi, Akita, Toyama, Fukui, Yamanashi, Shiga, Nara, Wakayama, Tottori, Tokushima, Ehime, and Kochi, the number of new cases of infection is approximately 72, 151, 161, 149, 171, 289, 375, 460, 341, 189, 137, 153, and 174, respectively. In some areas, the number has increased rapidly, with a ratio to that for the previous week of more than 2. The use rate of beds is slightly more than 60% in Iwate, Shiga, and Wakayama, slightly more than 70% in Yamanashi and Nara, slightly more than 30% in Toyama, Tokushima, Ehime, and Kochi, and slightly more than 20% in Miyagi, Akita, and Tottori.

Future outlook and measures to be taken

• The number of new cases of infection nationwide is increasing rapidly, with replacement by the Omicron variant. Along with the rapid increase in the number of infected individuals due to increased opportunities for contact, such as while dining out at the end and beginning of the year, the infection is also beginning to occur at homes, workplaces, schools, medical institutions, and nursing welfare facilities, and also to spread from such places. The nighttime population is generally decreasing in the areas under priority measures, although it is increasing in some areas. The ratios of new cases for this week to that for the previous week and the effective reproduction numbers indicate a decreasing trend or a state in which the increase is halting in some areas, as well as a downward trend in the pace of the increase. However, given the characteristics of the Omicron variant and the changes in parameters such as the positive PCR test rate, the spread of infection is expected to continue nationwide, even though its pace is slowing. It is therefore necessary to take measures promptly, based on the characteristics of the Omicron variant and the current infection status.
• In many areas, the numbers of persons who are positive for the COVID-19 and in close contact with infected individuals are increasing at schools, kindergartens, nursery schools, etc. In areas where the infection is spreading, it is necessary to strengthen and thoroughly enforce basic infection prevention measures at these facilities. When providing vaccination services at shortened intervals for the general public, vaccinations need to be promoted for teachers and other staff who are working at these facilities. It is also necessary to consider securing educational opportunities through measures such as staggered attendance and online lessons, and maintaining social functions.
• At nursing welfare facilities, infection prevention measures should also be strengthened. Promotion of booster vaccinations for residents and staff, as well as aggressive testing for staff is required. For infection control and medical care at facilities, external support is important.
• Individuals infected with the Delta variant, which is more likely to cause severe symptoms, are still detected, although it is being replaced by the Omicron variant. In Okinawa, where a prevalence of infections with the Omicron variant was seen earlier than in other areas, the number of infected individuals is decreasing among young people, but continues to increase in persons in their 70s, along with a continuous increase in the number of hospitalized patients. The number of infected individuals at nursing welfare facilities is also increasing. Similar trends may be seen in other areas, in the future. Due to the rapid spread of infection, mainly among young people, the number of patients under condition monitoring and the number of home care recipients continue to increase, and systems for medical care provision system and other services for mild and moderate patients are becoming strained. In addition, the spread of infection in the elderly may increase the number of severe patients, in the future. Attention should also be given to a possible increase in the number of infected individuals requiring hospitalization, as test-positive persons with an underlying disease may require hospitalization due to disease exacerbation by the infection, even in cases where they do not have COVID-19 pneumonia.
• Each year, many cases of emergency transportation usually occur during this period. According to a status survey on cases of emergency transportation difficulties, cases of suspected non-COVID-19 have increased compared to cases of suspected COVID-19, in many municipalities. With a rapid increase in the number of cases of suspected COVID-19, cases of emergency transportation difficulties have exceeded those during the same period last year and during the spread of the infection last summer. There is already a significant burden on regular medical care, especially emergency medical care.

Findings on the characteristics of the Omicron variant

• [Infectivity/transmissibility]

  It has been confirmed that compared to the Delta variant, the generation time has shortened to approximately 2 days (approximately 5 days for Delta). The doubling time and incubation period have also shortened, the risk of re-infection and secondary infection after infection has increased, and the speed of infection spread is very fast.

• [Place/route of infection]

  In Japan, many cases of infection occur through the same opportunities as before (spending time indoors with insufficient ventilation, eating and drinking, etc.), and infection is considered to occur via the same routes as before (droplets, aerosol inhalation, contact infection, etc.).

• [Severity]

  It has been suggested that infection with the Omicron variant may present a relatively lower risk of hospitalization and aggravation than does the Delta variant. However, the number of cases of hospitalization due to the Omicron variant infection has already increased.

• [Duration of viral shedding]

  Viral shedding in individuals infected with the Omicron variant decreases over time, regardless of vaccination status. In patients with symptoms, it has been shown that the possibility of viral shedding after Day 10 (when the date of onset is regarded as Day 0) is as low as in the case of infection with the conventional strain. In patients with no symptoms, it has been shown that the possibility of viral shedding is low 8 days after the date of diagnosis.

• [Vaccine effect]

  For infection with the Omicron variant, the preventive effect of a first vaccination against disease onset is markedly reduced, but its preventive effect on aggravation is maintained at a certain level. It has also been reported that booster shot improves the infection-preventing effect and hospitalization-preventing effect for infection by the Omicron variant.

Efforts based on the spread of infection with the Omicron variant

• [Test/diagnosis and surveillance in areas with a rapid spread of infection]

  A test/diagnosis system and the processing of notifications to public health centers are becoming strained, and there are concerns regarding discrepancies between the published data and the actual status. It is necessary to consider effective and appropriate surveillance, in order to properly grasp the trend of occurrences. Tests and active epidemiological surveys should be prioritized based on the findings obtained thus far. Regarding free tests for people who are worried about infection and wish to undergo testing, attention should be paid to a rapid increase in demand for tests as well as test availability, and a system to ensure prioritized testing needs to be secured.

• [Monitoring system for mutant strains in Japan]

  While the infection is spreading nationwide, it is necessary to maintain a surveillance system according to the local infection status, including the situation regarding replacement with the Omicron variant. For severe patients, clusters, or other applicable cases, a genome analysis should also be performed to identify variants such as the Delta variant. In addition, in some areas overseas, the number of cases of infection with the BA.2 lineage is increasing. Currently, the mainstream of the Omicron variant in Japan is the BA.1 lineage, but the BA.2 lineage has also been detected in quarantine and in Japan. Monitoring must be continued by a certain number of genome analyses. In comparison between the BA.1 and BA.2 lineages, differences in hospitalization rates are not clear at this time.

• [Measures taken by local governments]

  Based on the infection status of the region and forecasts of the numbers of infected cases and severe cases, local governments must work flexibly to secure the required number of beds and healthcare professionals, secure the functions of public health centers, which are indispensable for local communities, along with support for strengthening the healthcare center system, and establish home-visit and online medical care systems for home care recipients. At that time, it is necessary to secure a system for prompt administration of oral therapeutic drugs and neutralizing antibody drugs, for patients at risk of developing severe disease, such as elderly patients and patients with underlying diseases. As patients with acute diseases other than COVID-19 who require emergency transportation often appear during the winter, attention should be given to the balance between medical care for COVID-19 and regular medical care. If the infection spreads rapidly, it is necessary to take concrete actions to ensure that people have prompt access to consultation and condition monitoring according to the infection status in the area, and to prevent a collapse of outpatient care services.

• [Reinforcement of provision of information to people who have not been vaccinated or who are eligible for booster vaccination]

  It is particularly important to promote the vaccination of unvaccinated persons. Local governments are required to provide information to persons who have not been vaccinated. At the same time, booster vaccinations, which have already been started, must also be implemented steadily. The number of elderly infected individuals may continue to increase in the future. Therefore, it is necessary to further accelerate vaccinations for the elderly and other eligible persons, and also to successively provide vaccination services ahead of the original schedule for the general public as well, as much as possible.

• [Quarantine measures]

  The waiting period after entering Japan has been further reduced from 10 days to 7 days. It is necessary to continue to verify future quarantine measures, while taking into account the prevalence of variants such as the Omicron variant in Japan and overseas. For individuals found to be positive by an entrance test, a whole-genome analysis should continue to be performed, to monitor the strains that are spreading overseas.

An immediate review of the business continuity plan of each local business is required

• Due to the rapid spread of infection in the region, infections among employees and their families, or withdrawal from the workplace due to close contact, are increasing, especially at medical institutions and nursing welfare facilities. Since similar situations can occur in other workplaces that are necessary for social maintenance, their business continuity plans must be inspected urgently. In addition, from the viewpoint of preventing the further spread of infection while maintaining socioeconomic activities as much as possible, the scientific findings regarding the Omicron variant were again verified, to shorten the period of condition monitoring for persons in close contact with infected individuals, and to allow local governments to further shorten the period based on the results of tests for 2 consecutive days, for persons who are necessary for social maintenance. In patients with no symptoms, the period of recuperation can be shortened. It is important to continuously and appropriately review the period of condition monitoring and the period of recuperation.
• In order to maintain social functions, attendance at workplaces and opportunities for contact must be reduced by utilizing telework, promoting the taking of time off, and through other measures. In addition, occupational booster vaccination should be actively promoted.

It is essential to widely share the current infection status with citizens and business operators, and cooperate toward preventing the spread of infection.

• Governments, business operators, and citizens need to act with an awareness that the infection, mainly the Omicron variant is still spreading, not only in areas under priority measures, but throughout Japan. In addition, booster vaccinations are effective in preventing disease aggravation/onset.
• Regarding infection with the Omicron variant, basic prevention measures are still important, and people including vaccinated individuals should continue to ensure the proper wearing of nonwoven masks, hand washing, ventilation, etc. The risk of infection becomes highest when the three Cs (crowded places, closed spaces, and close contact) overlap. However, people should avoid even a single C, as much as possible, because the Omicron variant is highly transmissible.
• Crowded places and other places with a high risk of infection must be avoided when going out. Activities with small numbers of people. When it is necessary to use restaurants, it is necessary to select a third party-certified restaurant that implements infection control measures such as good ventilation, with as few people as possible, to avoid loud noises and long hours, and to wear a mask when not eating or drinking.
• In order to protect the lives of both yourself and your family, and at the same time prevent the spread of infection by the Omicron variant, it is necessary to refrain from going out if you feel a little unwell, such as a mild fever or fatigue, and to be examined and receive tests according to government policy.

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