"Isn't it entered the '8th wave' of the new corona?
" In Hokkaido, the number of new mutated viruses is increasing every day,
and experts and doctors are saying that they are entering a new wave and that a new wave has begun.
We interviewed when the infection peak of the "8th wave" is expected to occur, and what kind of measures are required.
(as of November 18)
Spread of infection in various places "8th wave"?
On November 15, the number of new coronavirus infections per day was 11,196 in Tokyo and 102,829 nationwide, the highest level since September 14.
In Hokkaido, the number of cases reached 11,112 on November 16, and has already passed the peak of the 7th wave, and the number of updates continues to be the highest ever.
Shigeru Omi, chairman of the government subcommittee, said on November 10, ``There is a difference in the speed of infection nationwide, but the infection is spreading. He showed the recognition that he is entering the 8th wave.
After that, on the 16th, Satoshi Kamasaki, executive director of the Japan Medical Association, said, "I can't help but think that a new wave has started. I have a sense of urgency that we need to improve the medical care system as quickly as possible. I am, ”he said, acknowledging that the 8th wave has started.
Then, on the 17th, an expert meeting of the Ministry of Health, Labor and Welfare pointed out that ``the number of new infections is expected to increase in the future, and there is a possibility that the infection will spread like the ``seventh wave'' of this summer.'' .
Why now "the eighth wave"?
'BA.5' reignites from the north
Why is the infection spreading now?
One of the clues that experts are paying attention to is that the spread of infection is not starting in big cities.
Until now, the spread of infection started in the metropolitan area with a large population and spread to various places as people moved, but this time it started in Hokkaido and the Tohoku region.
And even now, the Omicron stock "BA.5", which has become mainstream since the "7th wave" this summer, continues to be the most common.
At the expert meeting on the 17th, the percentage of people with immunity was high in areas where there were many people infected with "BA. It was shown that the percentage was low and the number of infected people was increasing.
Takaji Wakita, chairman of the Ministry of Health, Labor and Welfare Experts' Meeting, said at a press conference after the expert meeting, "In Okinawa, there was a very large spread in the summer, but now the number of infected people is at a very low level. have acquired immunity to BA.5 and are resistant to BA.5 epidemics.On the other hand, it is recognized that the spread of infection is increasing in areas that did not spread so much in the summer.Hokkaido The number of infected people is high in Tohoku and Hokuriku."
Atsuro Hamada, a specially appointed professor at Tokyo Medical University who is familiar with infectious diseases, including the situation overseas, said, "The current epidemic seems to be a situation where the embers of the '7th wave' 'BA.5' are rekindled. Although the number of cases is increasing in metropolitan areas, the number of infections is increasing significantly in regional cities.In areas where the number of infected people was relatively small during the "seventh wave" and the acquisition of immunity due to infection was low, the embers are reignited. It's reasonable to think that there is," he said.
The re-expansion of infection due to "BA.5" also occurred in Europe around October.
According to the site "Our World in Data" operated by researchers at the University of Oxford, England, the number of new infections per million people (per week average per day) will be around mid-October in Germany. With 1,300 people, it exceeded the peak in July this year, and in France, it reached about 840 in mid-October, the highest level since July.
After the expert meeting on the 17th, Chairman Wakita expressed the view that the peak of future infections due to "BA.5" may come within the year.
In addition, Professor Hiroshi Nishiura of Kyoto University, who specializes in mathematical epidemiology, said after the meeting, "As seen in Hokkaido, the spread of infection is progressing while spreading regionally. (Even if it does), the decline will be gradual, and I think it will smolder over time."
Furthermore…an increase in new mutant viruses
What is even more concerning in the future is the increase in mutant viruses such as the "BQ.1" strain, which is one of the Omicron strains.
These mutant viruses are likely to escape the immunity gained from previous infections and vaccinations.
In the United States, it is increasing in place of "BA.5".
According to the CDC = Center for Disease Control, the mutant viruses detected in the week until November 12 were ▽ "BA.5" at 29.7%, ▽ "BQ.1.1" at 24.1%, and ▽ "BQ.1". 20.1%, ▽ ``BF.7'' is 7.8%, ▽ ``BA.4.6'' is 5.5%.
These new mutant viruses have also been confirmed in Japan.
According to the materials submitted to the monitoring meeting in Tokyo on November 17, the ratio of mutated viruses detected in October was overwhelmingly 90.5% for ▽ "BA.5", but ▽ "BA.2.75". is 2.5%, ▽ ``BQ.1.1'' is 2.4%, ▽ ``BF.7'' is 2%, ▽ ``BQ.1'' is 0.7%, and ▽ ``XBB'' is 0.7%.
"BA.5" accounted for 98.4% in September, so it is on a downward trend.
The "BQ.1" lineage virus is a virus with further mutations of "BA.5".
'BA.2.75.2' has been detected in the United States, India, European countries, etc., and three more mutations have been added to 'BA.2.75', which has been mutated by 'BA.2'.
"XBB" is a type of virus called "recombinant" that combines a mutant virus derived from "BA.2" and a mutant virus derived from "BA.2.75".
Hamada, a specially appointed professor at Tokyo Medical University, points out that if such a new mutated virus spreads in Japan, the ``eighth wave'' may grow.
Atsuro Hamada, Specially Appointed Professor, Tokyo Medical University
"There are two mutant viruses that are currently attracting attention, the ``XBB'' and ``BQ.1'' strains, but ``XBB'' has not spread much worldwide. ``BQ.1'' " is being replaced from "BA.5" in Europe and the United States.In Europe and the United States, the number of infected people is not increasing rapidly, but in the future, if many new mutant viruses enter Japan, " There is a possibility that the 8th wave will become large.In December, it will be in such a situation.We need to see the progress."
AI prediction: Depending on the mutated virus, it may exceed the “seventh wave”
How far will the infection spread in the future?
A group led by Professor Terumasa Hirata of Nagoya Institute of Technology used AI (artificial intelligence) to create a "BQ Assuming that new mutated viruses such as ".1" will increase, we predicted the future infection situation.
According to this, the number of infected people in Tokyo is expected to start increasing in earnest from mid-November to late November.
And, assuming that the infectivity of "BQ.1" and others is 1.2 times that of "BA.5" and that there is no effect of immunity due to past infections, the average weekly average in Tokyo is It is predicted that the number of infected people will reach about 30,000 in mid-December, and about 36,000 in mid-January 2023, exceeding the peak of the "seventh wave."
According to this assumption, from mid-January to late February 2023, more than 20 people a day will die from the coronavirus in Tokyo.
Also, assuming that the infectivity of BQ. It became a prediction.
Professor Akimasa Hirata of Nagoya Institute of Technology
"Assuming the impact of mutated viruses such as `` BQ. The characteristics of the mutant virus are not yet well understood, but if it is highly contagious and immune evasion is strong, it is predicted that the number of infected people will increase considerably toward the end of the year."
In the future, the impact of the World Cup
From now until the end of the year, it is expected that there will be more opportunities for people to come into contact with each other.
In addition to this, Specially Appointed Professor Hamada of Tokyo Medical University says that it is necessary to pay close attention to the infection situation overseas now that border measures are being relaxed.
In the past week, the spread of infections not only in Japan but also in East Asia and Southeast Asia such as South Korea, Indonesia, and Malaysia has been noticeable, but the spread of infections in the United States, which is due to Thanksgiving in late November, and the soccer world. We should also pay attention to the impact of holding the cup and the Qatar tournament.
Professor Hamada said, ``In the United States, the number of new coronavirus infections has been increasing around Thanksgiving Day. It is said that about 1.2 million people from all over the world will visit Qatar for the World Cup in 2020. So far, the Tokyo Olympics and Paralympics and the Beijing Olympics and Paralympics have both been held under strict infection control measures. However, this time it will be held while the measures have been considerably relaxed.It is necessary to assume that the infection will spread during the World Cup period, and that the infection will spread in each home country after returning home." .
Co-epidemic with influenza
It has been pointed out that we should prepare for the simultaneous epidemic of the new coronavirus and influenza in the winter.
Currently, the number of influenza patients is at a lower level than before the corona, and the number of patients per medical institution was "0.08" in the week until November 13, which is "1", which is considered to be an epidemic. It's well below.
However, compared to last year and the year before, when there were almost no patients, the number of patients per sentinel in the Kansai area, the number of facilities closed, school closures, and class closures was reported at an expert meeting of the Ministry of Health, Labor and Welfare on new coronavirus countermeasures on the 17th. is on the rise, and it is necessary to pay close attention."
In Australia, in the southern hemisphere, where the season is opposite to Japan, the number of infected people increased sharply from May to June this year, surpassing the large-scale epidemic before Corona.
In addition, according to a report by the World Health Organization (WHO), the number of cases has increased in the United States and Canada over the past few weeks, and in Europe, although it is at a low level, it is also on the rise.
Professor Nishiura of Kyoto University said, "Influenza is currently increasing at a very slow pace, and it is speculated that the maximum number of infected people will be reached after school reopening at the beginning of the year. The peak is at least expected to shift," he commented.
Hamada, a specially appointed professor at Tokyo Medical University, said, "Even in Japan, the number of children infected is increasing in some areas, and classes are being closed. It is better to think that winter epidemics will occur in the future. New corona It can be given at the same time as the vaccine for the flu, so I would like you to get the flu vaccine now."
Experts call for vaccination
How can we limit the number of infected people, reduce the number of hospitalizations, and avoid medical strains?
Experts are calling for vaccination first.
At an expert meeting of the Ministry of Health, Labor and Welfare, it is recommended that people over the age of 12 who have completed the first vaccination should be vaccinated against the Omicron strain by the end of the year, and that infants and children in elementary school should also be vaccinated. is calling
Wakita, chairman of the expert meeting, said, ``There are concerns about the side effects of vaccines, and there are few cases of severe illness even if infected, but it is not impossible that the infection will become severe, and even young people It is said that there are many after-effects.It is important to be vaccinated properly to avoid infection.Vaccination has the merit of not being infected and suppressing the severity of the disease, protecting one's family, suppressing the epidemic, and providing medical care. It also has the advantage of reducing the load on the
In addition, Professor Hamada of Tokyo Medical University said, "Since it is said that new mutant viruses escape immunity, some people may think that vaccination will not be effective, but it will never work. No. The vaccine for the Omicron strain, which is currently inoculated, is thought to be effective against "BQ.1" and "XBB", which may spread in the future. I want you to be vaccinated and prepare for the 'eighth wave' in winter."
No change in measures to be taken
As we enter the year-end party season, it is important to reconfirm the basic measures.
▽ If you have symptoms such as fever, do not go to school or work, and avoid contact with other people as much as possible.
rest is important.
▽Wear a mask when disinfecting your hands and when talking to people indoors at a close distance.
▽ Thoroughly ventilate restaurants and other establishments.
Professor Hamada said, "I want you to continue to take measures such as wearing masks, washing your hands, and avoiding crowds. From now on, the season for year-end parties, New Year's parties, and homecomings will come. Depending on the epidemic situation, we may have to cancel. It may be. It is important to take action while carefully watching the infection situation."