102nd Meeting of the COVID-19 Advisory Board of the Ministry of Health, Labour and Welfare (October 12, 2022) Material 1

Evaluation of the latest infection status, etc.

Overview of the infection status

• The number of new cases of infection nationwide (by date of report) continued to decrease to approximately 143 per 100,000 in the last week, with a ratio to the previous week of 0.73.
  However, attention must be paid to the impact of increased opportunities of contact due to consecutive holidays on the infection status.
• With the decrease in the number of new cases of infection, the number of patients receiving treatment is also decreasing. The use rate of beds is also decreasing and improvement is seen in the situation of the medical care provision system.
  The numbers of severe cases and deaths continue to show a downward trend.

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 the reporting dates.

1. Hokkaido

   The number of new cases of infection was approximately 223 (approximately 216 in Sapporo City), and the ratio to the previous week is 0.80. The use rate of beds is approximately 20%.

2. North Kanto

   In Ibaraki, Tochigi, and Gunma, the numbers of new cases of infection were roughly 153, 130, and 162, respectively, and the ratios to the previous week were 0.67, 0.70 and 0.72, respectively.
   The use rates of beds are slightly below 30% in Ibaraki, slightly below 20% in Tochigi, and slightly above 20% in Gunma.

3. Tokyo metropolitan area (Tokyo and 3 neighboring prefectures)

   The number of new cases of infection in Tokyo was approximately 131, and the ratio to the previous week was 0.67. The use rate of beds is slightly over 10%, and the use rate of beds for severe cases is slightly below 10%.
   In Saitama, Chiba, and Kanagawa, the numbers of new cases of infection were approximately 121, 116, and 128, respectively, and the ratios to the previous week were 0.69, 0.71, and 0.69, respectively.
   The use rates of beds are slightly over 20% in Kanagawa, approximately 20% in Saitama and slightly over 10% in Chiba.

4. Chukyo/Tokai

   The number of new cases of infection in Aichi was approximately 113, and the ratio to the previous week is 0.61. The use rate of beds is slightly over 20%.
   In Gifu, Shizuoka, and Mie, the numbers of new cases of infection were about 150, 143, and 186, respectively, and the ratios to the previous week were 0.66, 0.78, and 0.78, respectively.
   The use rates of beds are approximately 10% in Gifu, slightly over 10% in Shizuoka, and approximately 20% in Mie.

5. Kansai area

   The number of new cases of infection in Osaka was approximately 143, and the ratio to the previous week was 0.69. The use rate of beds is slightly over 10%, while the use rate of beds for severe cases is below 10%.
   In Shiga, Kyoto, Hyogo, Nara, and Wakayama, the numbers of new cases of infection were approximately 146, 110, 114, 134, and 167, respectively, and the ratios to the previous week were 0.64, 0.69, 0.73, 0.79, and 0.86, respectively.
   The use rates of beds were slightly over 20% in Shiga, slightly over 10% in Hyogo, Kyoto and Nara, and approximately 10% in Wakayama.

6. Kyushu

   The number of new cases of infection in Fukuoka was approximately 114, and the ratio to the previous week was 0.74. The use rate of beds is slightly over 10%.
   In Saga, Nagasaki, Kumamoto, Oita, Miyazaki, and Kagoshima, the numbers of new cases of infection were approximately 123, 115, 130, 131, 135, and 129, respectively, and the ratios to the previous week were 0.57, 0.67, 0.74, 0.73, 0.75, and 0.70, respectively. The use rates of beds are slightly over 10% in Kumamoto, Oita, and Miyazaki, slightly below 20% in Nagasaki and Kagoshima, and approximately 10% in Saga.

7. Okinawa

   The number of new cases of infection was approximately 142, and the ratio to the previous week was 0.70. The use rate of beds was slightly over 10%, while the use rate of beds for severe cases was approximately 10%.

8. Areas other than the above

   In Fukushima, Nagano, and Hiroshima, the ratios to the previous week were 0.91, 0.91 and 0.92, respectively. The use rate of beds was slightly below 10% in Fukui and Yamanashi.

Infection status and future outlook

Infection status

• The number of new cases of infection continues to decrease in all regions. However, outbreaks in facilities for elderly people and medical facilities have decreased despite continuing to some extent.
• The number of new cases of infection in each age group continues to decrease nationwide, but per population, the numbers are higher in younger age groups. The number of new cases of infection among elderly people has also been decreasing, and the numbers of severe cases and deaths also continue to show a downward trend.
• As the provisional report on the deaths of children since January this year suggests, attention must be paid to the occurrence of severe cases and deaths associated with an increase in the number of infected children.

Future outlook

• Regarding the future infection status, the number of infections may gradually decrease or remain at a constant level despite uncertainty, based on the short-term forecast in large cities. It is also necessary to pay attention to the impact that increased contact opportunities due to consecutive holidays and tourism will have on the infection status. In addition, based on the trends of the past two years, there are concerns about the spread of the new coronavirus infection this winter, an earlier seasonal flu epidemic than usual, and that these two may occur simultaneously.

Factors that increase and suppress infection

1. [Immunization by vaccination and infection]

   Immunity acquired from vaccination and natural infection may decline over time. Although the vaccination rate is higher among people in their 60s and older than those in their 20s to 40s, the acquisition of immunity by infection is lower, and there is concern about the spread of infection among elderly people in the future.

2. [Contact patterns]

   The nighttime population is decreasing in many areas due to a continued decline in temperature and rainfall. This may have contributed to the recent decrease in the number of infected people. However, there is also concern that the nighttime population will increase toward the end of the year.

3. [Epidemic strain]

   The BA.5 lineage has largely become mainstream and is replacing others. At present, there is no trend toward further replacement by other lineages.

4. [Climatic factors]

   Weather conditions will be favorable for ventilation for a while, but ventilation may be difficult on days with high temperatures or heavy rainfall.

Situation of the medical care provision system

• Nationwide, the use rate of beds is decreasing due to continued improvement of the infection situation, at a low level below 30% in all areas.
  The use rate of beds for severe cases is also declining, and areas with a use rate of 0 are increasing.
• Nationwide, the situation of the medical care provision system is improving, including general medical care. However, in the field of nursing care, patients are being treated in the facilities and infections are seen among workers.

Measures to be taken

Basic concepts

Regarding measures under the Infectious Disease Control Law, appropriate medical care will be provided to elderly people and persons at risk of severe illness, and the period of medical treatment of patients will be reviewed.

The spread of infections this summer and measures to handle the current infection situation will be reviewed, and measures will be taken based on the assumption that infections may spread due to a simultaneous epidemic of seasonal influenza this fall.

Each citizen will be asked to take voluntary actions to prevent infection, while strengthening and prioritization of the health care system will be promoted to protect those at high risk of becoming seriously ill, such as elderly people, and to ensure regular medical care.

The national and local governments will remind the public of the need for routine infection control measures and take measures to support the public's efforts to prevent infection.

1. 1. Further promotion of vaccination
   • As for the “vaccine for the Omicron variant," vaccination of all persons aged 12 and over who have completed the first vaccination should proceed.
   • Vaccination for the BA.4 and BA.5 lineage has also started. As both vaccines for the BA.1 and for the BA.4 and BA.5 lineages are expected to be more effective than the previous vaccines, it is necessary to proceed with vaccination with vaccines that can be given earlier. The vaccination interval was set at 5 months, but it is necessary to consider shortening the vaccination interval in light of overseas trends, and to reach a conclusion by the end of October.
   • Those who have not received vaccination will be encouraged to consider getting the initial vaccination as soon as possible.
   • For children (ages 5 to 11), booster vaccinations will be promoted along with the initial vaccination.
   • The initial vaccination for children (aged 6 months to 4 years) has been approved by the PMDA and positioned as an extraordinary vaccination, and initial vaccination in this age group will proceed.
2. 2. Use of tests
   • Based on the recommendations of the 17th meeting of the Novel Coronavirus Subcommittee, the national and local governments are required to secure a system that enables testing, and further utilize testing.
   • Perform frequent tests (about 2 or 3 times a week for facility workers) for workers at facilities for elderly people.
   • Establishment of a self-testing system for fever outpatients should be further promoted, in which patients with symptoms can self-test using an antigen qualitative test kit, and if the result is positive, they can promptly undergo health observation at a health follow-up center, etc.
   • Promote further utilization of antigen qualitative test kits, such as by online sales through OTC.
3. 3. Securing a medical care provision system

   Prefectural governments must take measures to avoid overcrowding of beds and fever outpatient sections with the support of the national government.

   • In addition to facilitating the use of available hospital beds and developing temporary medical facilities to supplement hospital beds, making efforts to avoid a shortage of hospital beds and emergency medical care, such as utilization of lodging facilities and resting beds
   • Making appropriate adjustments so that patients requiring inpatient treatment can be hospitalized preferentially, performing frequent tests at facilities for elderly people, etc., and further strengthening medical support
   • Securing and expanding logistical support hospitals, and improving the hospital turnover rate, such as by dissemination of the standard for early discharge of 4 days, as a rule
   • Promotion of effective and less burdensome measures against infection, such as flexible and efficient use of hospital beds through zoning of each hospital room
   • Expansion and promotion of fever outpatient services, including the use of online medical care, etc., and further promotion of the development of a “fever outpatient self-examination system”
   • Local residents should be informed that they should refrain from visiting an emergency outpatient unit only to receive a precautionary examination without symptoms, according to the actual situation in the region. In addition, in order to respond to concerns and questions at the time of worsening physical conditions, the consultation service by healthcare professionals via telephone should be thoroughly publicized, and this service should also be strengthened.
   • Ensuring that workplaces and schools do not require test certificates at the start of medical treatment
4. 4. Change of thinking about medical treatment and review of all-case notification
   • Based on the review of the nationwide notification of all cases that began on September 26th, the health care system will be strengthened and prioritized to protect those who are at high risk of becoming seriously ill, and it is necessary to establish an environment where young people with mild symptoms, who are not subject to notification, can be assured of treatment at home.
5. 5. Review of home care period
   • Since the risk of infection remains in the shortened period of home care for those who test positive, they should monitor their own physical condition, such as measuring temperature, and take thorough measures against infection when going out. In addition, they must be asked to avoid contact with people who are at risk of becoming seriously ill, such as the elderly.
   • To allow the minimum necessary outings, such as shopping for groceries, after 24 hours have passed since symptoms have subsided or when there are no symptoms, it is necessary to take voluntary actions to prevent infection, such as wearing a mask when going out or coming into contact with people, keeping contact with people to a short period of time, and not using public transportation.
6. 6. Surveillance
   • Deterioration of the accuracy of current surveillance is a concern due to the limited scope of notification, prioritization of notification items, delays in testing and diagnosis/reporting due to many infections, and changes in healthcare-seeking behavior. It is necessary to promptly promote consideration of effective and appropriate surveillance to grasp the epidemic status.
     It is also necessary to continue monitoring the trends of variants through genomic surveillance.
7. 7. Effective ventilation
   • Based on the recommendations of the 17th meeting of the Novel Coronavirus Subcommittee, it is necessary to publicize and recommend effective ventilation methods to prevent insufficient indoor ventilation (how to create airflow considering aerosols, installation of partitions that do not block airflow, etc.).
8. 8. Re-inspection and implementation of basic infection control

   Re-inspection and implementation of the following basic infection control measures are needed.

   • Continue proper wearing of nonwoven masks according to the situation, hand hygiene, thorough ventilation, etc.
   • Avoid situations with a high risk of infection, such as the three Cs, congestion, or loud voices.
   • Eating and drinking should be done with as few people as possible, and masks should be worn except while eating and drinking.
   • People with symptoms such as sore throat, cough, and fever should refrain from going out.
   • Refer to guidelines for hospital visits and use of an ambulance.
   • To reduce the chances of contact as far as possible, it is necessary for measures at the workplace, such as again promoting the use of telework.
   • Organizers of events, meetings, and such should fully evaluate the epidemic situation and risk of infection in the area, and consider whether or not to hold the meeting, and if it is held, measures should be taken to minimize the infection risk.

<< Reference: Findings on the characteristics of the Omicron variant and its sublineages >>

1. [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. According to the reported data, pre-symptomatic transmission has probably occurred to some extent as with the previous strains.

2. [Place/route of infection]

   In Japan, many cases of infection have occurred through the same opportunities as before (spending time indoors in locations with inadequate ventilation, eating and drinking, etc.), and infection is considered to have occurred via the same routes as before (droplets adhering to mucosa, aerosol inhalation, contact infection, etc.).

3. [Severity]

   It has been suggested that infection with the Omicron variant presents a lower risk of hospitalization or aggravation than the Delta variant. However, analyses to date show that the fatality due to infection with the Omicron variant is higher than that due to seasonal influenza. It is also suggested that the incidence of pneumonia is higher than that of seasonal influenza, but given the limited data, it needs to be investigated by various analyses. In the death toll from the previous outbreak compared to last summer's outbreak, it is reported that there are many cases in which the new coronavirus infection is not the direct cause of death, for example, people who have been in a facility for the elderly before the infection are infected and die due to the worsening of the underlying disease. In the current spread of infection, the rate of severe cases has continued to decrease and the ratio of elderly people among hospitalized patients has increased compared to the previous summer, following the previous outbreak. Among the deaths in this outbreak, mechanical ventilation/nasal high flow use rates and steroid prescription rates have decreased compared to the previous outbreak.

   Among fatal cases in which endogenous death was identified in infected children, cases without underlying diseases were also found. Preliminary reports on the results of on-site investigations have stated that it is necessary to pay attention to neurological symptoms such as convulsions and disturbance of consciousness, and systemic symptoms other than respiratory symptoms such as vomiting and poor oral intake.

4. [Virus shedding period]

   According to Japanese data, risk of infection remains until 10 days after onset, and infectivity is high until 7 days after onset. Even after waiting for 5 days, 1/3 of patients are still shedding infectious viruses. On Day 8 (after waiting 7 days), most patients (approximately 85%) had not shed infectious virus, and it was reported that even in those who shed the virus, the amount of virus decreased to one-sixth after 7 days compared to the initial stage.

5. [Vaccine effect]

   For infection with the Omicron variant, the preventive effects of a first vaccination against infection and disease onset are markedly reduced. Its preventive effect on hospitalization is reported to be maintained at a certain level for the first 6 months, but subsequently decreases to 50% or less. On the other hand, it has been reported overseas that a third vaccination restores the infection-preventing effect, onset-preventing effect, and hospitalization-preventing effect against infection by the Omicron variant, and information on how these vaccine effects are attenuated after a third vaccination has become available. Regarding the fourth vaccination, it has been reported that while the preventive effect against aggravation was not reduced for 6 weeks, the preventive effect against infection lasted only for a short time.

6. [Sublineages of the Omicron variant]

   Worldwide, the proportion of the BA.5 lineage is increasing while the number of positive cases increases, suggesting that this lineage is superior to the BA.2 lineage in terms of causing an increase in the number of infected people, but currently the number of positive cases is decreasing. The BA.5 lineage has shown a tendency to escape existing immunity compared with the BA.1 and BA.2 lineages, but no clear findings on the infectivity have been shown. The effective reproduction number of the BA.5 lineage calculated based on the data of Tokyo was about 1.27 times that of BA.2. It was also estimated that it was about 1.3 times higher in samples collected from private testing institutions nationwide.

   According to the WHO report, the severity of BA.5 lineage shows both increased and unchanged data compared to the existing Omicron variants, and continued information collection is needed. In addition, the pathogenicity of the BA.5 lineage is reportedly higher than that of the BA.1 and BA.2 lineages, based on Japanese laboratory data, but it has not been confirmed clinically at this time. According to genomic surveillance in Japan, the detection rate of the BA.5 lineage has increased, and the previous dominant variant has largely been replaced with this lineage.

   In addition, the BA.2.75 lineage, which has been reported mainly in India since June, and the BA.4.6 lineage reported mainly in the US and UK, have been detected in Japan. However, no clear findings have been obtained overseas regarding its infectivity or severity, compared with other lineages. It is necessary to continue to collect and analyze the situation and findings in other countries regarding these characteristics of the virus, and to continue monitoring by genome surveillance.

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