103rd Meeting of the COVID-19 Advisory Board of the Ministry of Health, Labour and Welfare (October 20, 2022) Material 1

Evaluation of the latest infection status, etc.

Overview of the infection status

• Nationwide, the number of new cases of infection (by date of report) was approximately 197 per 100,000 in the last week, and ratio to the previous week was 1.35. As the rate has increased, we need to carefully watch the speed of increase and also whether this trend will continue in the future.
  It is also necessary to pay attention to the future impact of increased contact opportunities due to the reactivation of socioeconomic activities on the infection status.
• In contrast, the use rate of beds is generally on a downward trend, at a low level. The numbers of severe cases and deaths have stopped decreasing.

Local trends

* The value of 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 397 (approximately 355 in Sapporo City), and the ratio to the previous week was 1.60. The use rate of beds is approximately 20%.

2. North Kanto

   In Ibaraki, Tochigi, and Gunma, the numbers of new cases of infection were approximately 190, 188, and 224, and the ratios to the previous week were 1.47, 1.34, and 1.35, respectively.
   The use rates of beds were slightly over 20% in Ibaraki and Gunma, and slightly over 10% in Tochigi.

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

   The number of new cases of infection in Tokyo was approximately 169, and the ratio to the previous week was 1.25. The use rate of beds was slightly over 10%, while the use rate of beds for severe cases was below 10%.
   In Saitama, Chiba, and Kanagawa, the numbers of new cases of infection were approximately 152, 145, and 146, respectively, and the ratios to the previous week were 1.23, 1.20, and 1.16, respectively.
   The use rates of beds were approximately 20% in Saitama, slightly under 20% in Kanagawa and slightly over 10% in Chiba.

4. Chukyo/Tokai

   The number of new cases of infection in Aichi was approximately 151, and the ratio to the previous week was 1.28. The use rate of beds was slightly over 20%.
   In Gifu, Shizuoka, and Mie, the numbers of new cases of infection were approximately 249, 191, and 217, and the ratios to the previous week were 1.46, 1.43, and 1.45, respectively.
   The use rates of beds were slightly over 10% in Gifu, slightly under 20% in Shizuoka, and approximately 20% in Mie.

5. Kansai area

   The number of new cases of infection in Osaka was approximately 205, and the ratio to the previous week was 1.40. The use rate of beds was slightly over 10%, while the use rate of beds for severe cases was below 10%.
   In Shiga, Kyoto, Hyogo, Nara, and Wakayama, the numbers of new cases of infection were approximately 220, 133, 157, 191, and 282, and the ratios to the previous week were 1.33, 1.22, 1.49, 1.47, and 1.75, respectively.
   The use rates of beds were slightly over 20% in Shiga, approximately 20% in Wakayama, and slightly over 10% in Hyogo, Kyoto and Nara.

6. Kyushu

   The number of new cases of infection in Fukuoka was approximately 153, and the ratio to the previous week was 1.38. The use rate of beds was approximately 10%.
   In Saga, Nagasaki, Kumamoto, Oita, Miyazaki, and Kagoshima, the numbers of new cases of infection were approximately 178, 148, 186, 188, 169, and 134, and the ratios to the previous week were 1.33, 1.25, 1.28, 1.41, 1.26, and 1.01, respectively. The use rates of beds were slightly over 10% in Kumamoto, Oita, and Kagoshima, approximately 10% in Nagasaki and Miyazaki, and slightly under 10% in Saga.

7. Okinawa

   The number of new cases of infection was approximately 132, and the ratio to the previous week was 0.85. The use rate of beds was approximately 10%, and the use rate of beds for severe cases was slightly under 10%.

8. Other areas than the above

   In Iwate, Yamagata, Toyama and Kagawa the ratios to the previous week were 1.53, 1.56, 1.51, and 1.60, respectively. The use rates of beds were slightly over 20% in Aomori, Akita, Fukushima, Ishikawa, Nagano and Hiroshima.

Infection status and future outlook

Infection status

• Nationwide, the number of new cases of infection increased and the ratios to the previous week in almost all regions are higher than 1. We need to carefully watch the speed of increase as well as whether this trend will continue in the future. It is also necessary to consider the effect of consecutive holidays in the last week. The numbers of new cases of infection have increased in many regions of northern Japan. There are also still mass infections in some facilities for elderly people and medical institutions.
• The number of new cases of infection by age group increased in almost all age groups, and new patients per population were higher in younger age groups. The number of new cases of infection among elderly people also increased, and the numbers of severe cases and deaths stopped decreasing.
• As the provisional report of deaths among 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 continue to increase despite uncertainty, based on the short-term forecast in large cities. It is also necessary to pay attention to the future impact of increased contact opportunities due to the reactivation of socioeconomic activities on the infection status.
• Based on the estimated trends of the past two years, there is concern about earlier spread of the new coronavirus infection this winter, an earlier seasonal flu epidemic than usual, which is at a low level at this point, and that these two may occur simultaneously.

Factors that increase and suppress infection

1. [Immunity as a result of 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.

2. [Contact patterns]

   The nighttime population is increasing in many regions. There is also a concern that the nighttime population will further increase toward the end of the year.

3. [Epidemic strain]

   In Japan, the BA.5 lineage has largely become mainstream, and is replacing others. At present, there is not a 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 a low temperature or bad weather such as heavy rainfall.

Situation of the medical care provision system

• Nationwide, the use rate of beds is generally decreasing and the rates in all areas are at a low level below 30%. The use rate of beds for severe cases is also at a low level, but we need to watch for effects associated with an increase in the number of new cases of infection.
• In the field of nursing care, patients are being treated in the facilities and infections are seen among workers.
• Cases of problems with emergency transportation remain on the same level nationwide both for suspected non-COVID-19 cases and suspected COVID-19 cases.

Measures to be taken

Basic concepts

• To prepare for re-spreading of the novel coronavirus infection and simultaneous seasonal influenza epidemics, measures to strengthen and focus the healthcare system should be taken for limited medical resources to provide appropriate medical care to elderly people and persons at risk of aggravation.
• Each citizen will be asked to take voluntary actions to prevent infection and strengthening and prioritization of the health care system will be promoted to protect those at high risk of aggravation, 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 older 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 sooner. As the vaccination interval from the last vaccination was shortened from 5 months to 3 months, all eligible persons will be asked to receive the vaccine for the Omicron variant during this year.
   • 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 is 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 should further utilize testing.
   • Performance of frequent tests (about 2 or 3 times a week for facility workers) for workers at facilities for elderly people.
   • Further promotion of the establishment of a system whereby patients with symptoms can self-test using an antigen qualitative test kit, and can then promptly undergo health observation at a health follow-up center, etc. if the result is positive.
   • Further promotion of the utilization of antigen qualitative test kits that are switched to OTC and are sold on the internet.
3. 3. Securing a medical care provision system

   Prefectural governments must take measures to avoid overcrowding of beds and fever outpatient clinics 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. Response to simultaneous epidemics of novel coronavirus infection and seasonal influenza
   • Assuming that there are many patients with fever during simultaneous epidemics, the following measures should be promoted according to the actual situation of each region: strengthening of fever outpatient clinics, strengthening of telephone and online examination services in preparation for cases of overcrowding at fever outpatient clinics, smooth supply of therapeutic drugs, expansion of health follow-up centers, securing of self-examination kits, and strengthening of the consultation system.
   • The prefectures will formulate plans to establish systems such as strengthening of outpatient medical care systems in accordance with the actual conditions in each region.
   • In addition, efforts will be made to provide information to the public and to call for cooperation at clinic visits/treatment according to the risk of aggravation.
   • To prevent the infection from becoming severe as far as possible when symptoms occur, vaccination against the new coronavirus and influenza virus should also be promoted among those to be vaccinated.
   • In case the number of infected persons increases extremely and hospitals are under severe strain, or changes in the characteristics of viruses increase the pathogenicity, a response depending on the situation is required, and includes requests/calls for residents and business operators to prevent spreading of the infection and to maintain the functions of medical systems, as well as highly effective measures to prevent the spread of infection including behavioral restrictions.
5. 5. Surveillance
   • The limited scope of notification of occurrence, notified items, delay in testing/diagnosis/reporting due to the many cases of the infection, changes in medical care-seeking behavior, etc. are raising concerns about deterioration of the current surveillance program’s accuracy. To understand the epidemiological status, an effective and appropriate surveillance program should be developed promptly.
     It is also necessary to continue monitoring the trends of variants through genomic surveillance.
6. 6. 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.).
7. 7. Re-inspection and implementation of basic infection control

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

   • 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, measures are necessary at the workplace are needed, such as and include again promoting the use of telework.
   • Organizers of events, meetings, etc., should fully evaluate the epidemic situation and risk of infection in the area, and consider whether or not to hold the gathering, and if it is held, measures should be taken to minimize the infection risk.
   • Since a risk of infection remains during the shortened period of home care of those who test positive, they should monitor their own physical condition, such as measuring their temperature, and take thorough measures against infection when going out. They must also be asked to avoid contact with people who are at risk of aggravation, such as elderly people.
   • 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 when having contact with people, keeping contact with people to a minimum period of time, and not using public transportation.

<< 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]

   While the BA.5 lineage continues to be mainstream in the world, there are many reports of sublineages of the Omicron variant and recombinants which have characteristic mutations in the spike protein. There are also sublineages for which superiority in an increase in infected patients has been indicated, including the BQ.1 and BQ.1.1 lineages (sublineages of the BA.5.3 lineage), which are frequently reported in Europe and the United States, as well as the XBB lineage (recombinant of the BJ.1 lineage [sublineages of the BA.2.10 lineage] and the BM.1.1.1 lineage [sublineages of the BA.2.75.3 lineage]), which has been reported mainly in India and Singapore. In particular, in the United States, there is concern that the proportion of the BQ.1 and BQ.1.1 lineages will increase in the future. However, no clear findings of infectivity and severity, etc. of these variants have been obtained. It is necessary to continue to collect and analyze the situation and findings in other countries regarding these characteristics of the new sublineages and recombinants, and to continue monitoring by genome surveillance.

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