What is the peak number of new corona “8th wave” infected people? What are the precautions for New Year's Eve?

[NHK] The trend of increasing new corona continues. Will the number of infected people increase in the new year's holiday? When will the 8th wave peak? The number of infected people is rapidly increasing...

The new corona is increasing.

Will the number of infected people increase in the new year's holiday?

When will the 8th wave peak?

What is the impact of China, where the number of infected people is rapidly increasing?

And how should we deal with it when there are no movement restrictions?

I have summarized what I have learned.

(as of December 26)

Number of infected people per day increased after leveling off

The number of people infected with the new corona per day was 206,943 nationwide on December 21, surpassing 200,000 for the first time in about four months, and was the highest in the "8th wave."

The weekly average number of infected people per day leveled off temporarily in early December, but has continued to increase since then.

An expert meeting of the Ministry of Health, Labor and Welfare said on December 21 that although the rate of increase in the number of infected people was slowing down, ``The increasing trend is continuing. It's wide," he analyzed.

In addition to infection by the Omicron strain BA.5, which has been the mainstream until now, it is believed that this is due to the fact that it is being replaced by a new mutant virus that is easier to escape immunity.

Professor Kazuhiro Tateda of Toho University, who is a member of the government subcommittee on new corona countermeasures, said, "In the year-end and New Year period, there are no restrictions on movement, and the number of infections is increasing due to increased contact opportunities such as Christmas, year-end parties, homecomings, and New Year's parties. It is necessary to be careful not to turn into

"8th Wave" Many people are dying

The concern about the "eighth wave" is that the number of people who die from corona infection is increasing compared to the number of infected people.

Since the Omicron strain became mainstream, the proportion of people who become infected and become seriously ill and the proportion of people who die has decreased, but as a result, more people have become infected than before. many people are dying.

Looking at the 8th wave this time, the number of infected people nationwide is about 160,000 per day on average for a week, exceeding 220,000, and has not reached the peak of the summer ``7th wave''. .

However, the number of people who died was 339 on December 22nd and 24th, which is close to the peak of the 7th wave.

Experts believe that

the rate of deaths, mainly among the elderly, may be increasing due to the lack of progress in vaccination against the Omicron strain,

and that the

number of infected people will increase in September this year.

Since the change in the reporting format, the accuracy of reporting has decreased, and it seems that more people who are infected do not seek medical attention. He points out that there is a possibility that

In addition to aggravation of respiratory diseases, there have been reports of cases of blood clots occurring after infection, and experts believe that it may be a disease of the heart and other circulatory organs.

(Professor Tateda)

"We are still at the beginning of the 8th wave, and the number of people dying is approaching the peak of the 7th wave this summer, and we are concerned that the infection will spread and the number of people who will die will increase further. The year-end and New Year holidays are already a time when the number of patients with common diseases increases and the medical system weakens, and it is possible that we may not be able to treat people with injuries due to accidents or illnesses such as heart disease.

” Atsuro Hamada, a specially appointed professor at Tokyo Medical University who is familiar with the situation, said, "While the number of people who have died is coming out, it is possible that the number of infected people is less than reported. There are actually more people infected, and there is a possibility that the infection situation has already reached the same level as the 7th wave."

Future infection situation AI analysis and prediction

What will happen to the infection situation in the future?

A big influence is the situation of contact between people.

On December 21, an expert meeting of the Ministry of Health, Labor and Welfare pointed out that in Tokyo, Aichi, and Osaka, the number of people in downtown areas between 8:00 and 10:00 p.m. has reached the highest level since the spread of the corona infection began. .

It is feared that there will be more opportunities for people to come into contact with each other at year-end parties and new year parties.

On the other hand, the number of people after 10:00 p.m. has not increased to a record high level, and chairman Takaji Wakita said, ``Even if you go to the downtown area for dinner, you tend to finish in a relatively short time and go home. I am being watched," he said.

How will the infection situation progress in the future?

A group led by Professor Akimasa Hirata of the Nagoya Institute of Technology is using AI (artificial) based on information such as the status of new mutated viruses, past infections, vaccination status, and the status of drinking parties that have appeared on Twitter. Analyzing with intelligence.

The average number of new infections per day in Tokyo was over 15,000 as of mid-December, and so far, according to the simulation based on the data up to December 5. is transitioning.

However, it is estimated that the number of infected people will increase significantly from late December to early January, or will be suppressed to some extent, depending on the scale of social activities such as year-end parties and new year parties. .

Assuming that the infectiousness of the new mutated virus is 1.2 times higher, and if social activities are modest, such as when year-end parties are held down, the number will rise gradually toward the beginning of the year, reaching approximately 19,000 people in early January. to peak.

On the other hand, if social activities are large, it is estimated that about 28,000 people will reach in early January.

(Professor Hirata)

"There are more keywords such as 'drinking party' seen on SNS compared to the previous year, but it has been suppressed to an increase of about 30%. The number of people at night has not increased so much, and after Halloween The rate of increase is relatively moderate compared to 2021. Although many people are gradually returning to their pre-coronavirus lives, they may be acting in moderation.However, 2021 will be the last week of December. Since then, human activity has suddenly returned, which has led to an increase in Omicron stocks.It is a time when there are more opportunities to move around and interact with people you don't usually meet, and there are few factors that will reduce the infection status."

“More people may die”

AI predicts that the number of infected people will peak in mid-January, and the number of deaths will increase later, so the high level may continue through February.

The number of people who die in Tokyo is expected to continue until February, with an average of 20 people per day for a week even if social activities are relatively suppressed.

It is estimated that it will not exceed the level of nearly 30 people per day, which was the peak of the 7th wave, but there is concern that more people may die in total because the high number will continue for a long time. doing.

Concerns over the spread of new mutated viruses

It is the replacement of a new mutated virus that can cause further infection expansion.

The Omicron strain "BA.5" is still the mainstream, but

▽ "BQ.1", which has a mutation in the spike protein part of "BA.5", and

▽ further mutations have been added to it .

The detection of “BQ.1.1” is increasing.

Together, these strains are called the "BQ.1" strain of the Omicron strain, and there are concerns about the spread of infection due to their strong ability to escape immunity.

According to the data of Tokyo, "BA.5" was 73.9% as of November, but as of December 22nd, the percentage has decreased to 68.1%.

In addition, "BQ.1.1" is 9.4% and "BQ.1" is 2.5%, which exceeds 10%.

In the United States, according to data from the CDC = Center for Disease Control, in the week ending December 24, ``BA.5'' was 6.9%, ``BQ.1.1'' was 35.7%, and ``BQ.1'' was 27.4%. The "BQ.1" line is the mainstream with more than 60%.

'XBB', which is a combination of multiple types of Omicron strains, also accounts for 18.3%.

According to the ECDC = European Center for Disease Control and Prevention, in seven countries such as France and Germany, in the two weeks until December 11, the "BQ.1" lineage accounted for 52.0%, the most, and the "BA.5" line was 31.1. %, "BA.2.75" is 8.2%, "XBB" is 6.5%, and so on.

On the other hand, in China, where the so-called "zero corona policy" is being reviewed and the infection is spreading, further mutations have been added to "BA.5", and "BF.7", which is said to easily escape immune attacks, is expanding. and

Hamada, a specially appointed professor at Tokyo Medical University, is concerned that the infection situation in China may affect neighboring countries such as Japan, and that the virus may mutate.

(Professor Hamada)

"'BF.7' is a mutation added to 'BA.5', so it has been pointed out that the infectivity may not change that much, but we need to pay attention. China. In January

, it is expected that there will be more movement in Japan and overseas as we approach the Lunar New Year, the Lunar New Year. It is necessary to assume that the infection status of neighboring countries, including China, will be affected.In addition, if an extremely large number of people are infected in China and it continues to spread in the future, the nature of the infection will change. There is also the possibility that new mutated viruses will be born.”

What we know about the effectiveness of vaccines

How well do we know how effective vaccines are?

It has been reported that BA.5, which is still mainstream, is effective.

According to the National Institute of Infectious Diseases, infection with ``BA. It was announced that the effect of preventing the onset was 71%, indicating that it was highly effective.

On the other hand, there are reports from various countries that vaccines are less effective against new mutated viruses.

A group led by specially appointed professor Yoshihiro Kawaoka of the Institute of Medical Science, the University of Tokyo conducted experiments using the blood of vaccinated people to find out what happens to the level of neutralizing antibodies that suppress the action of new mutant viruses. On December 7, it was published in an international infectious disease journal.

According to it, the value of neutralizing antibody was about 43 minutes compared to the conventional virus with "BQ.1.1" one to two months after 4 doses of the conventional vaccine. In 1 of "XBB", it was about 1/52, and it was found that it was easier to escape immune attacks.

Also, in December, a group from Columbia University in the United States and others published a report on the effectiveness of a vaccine for the Omicron strain against a new mutated virus in the scientific journal Cell.

According to it, when the conventional vaccine is inoculated 3 times and the vaccine for the Omicron strain is additionally inoculated, the neutralizing antibody value against "BQ.1.1" is about 41 minutes compared to the value against the conventional virus. It means that it was 1 of

Although the effect of preventing infection may be reduced, the group says, ``It has been shown that it is possible to reduce the severity of symptoms and reduce the risk of sequelae.''

Tetsuo Nakayama, a specially appointed professor at Kitasato University who is familiar with vaccines, says that the decrease in antibody levels does not mean that the vaccine will be ineffective against the new mutated virus.

(Professor Nakayama)

“In addition to antibodies, the ability to defeat infected cells, called cell-mediated immunity, is boosted by vaccination. It is possible to be infected, but it works well in terms of suppressing aggravation.In the future, new mutant viruses such as "BQ.1" will increase in Japan. I think it is a vaccine that is effective in terms of suppressing the severity of the disease even as we continue to develop it.”

Co-epidemic with influenza?

Another concern is that the number of flu patients is beginning to increase.

The number of patients per week per medical institution nationwide was 0.53, an increase from 0.25 the previous week.

If this number exceeds "1", it is considered to be a nationwide epidemic season, and it is still below.

However, in Aomori, Iwate, Tokyo, Kanagawa, Toyama, and Kumamoto, the number exceeded 1, and each prefecture announced that it had entered the epidemic season.

For the first time since the spread of the coronavirus began, there are concerns about the simultaneous epidemic of the coronavirus and influenza.

At the December 21 meeting of the Ministry of Health, Labor and Welfare's experts' meeting, they said, "The level is higher than in the last two years, and it is increasing recently." I think you need

Influenza is also increasing overseas, and the WHO = World Health Organization reported on December 12 that influenza is spreading worldwide.

In particular, North America has continued to increase sharply in recent weeks, with some indicators nearing or exceeding pre-Covid-19 epidemic peaks.

(Professor Hamada)

"Since there has been no major influenza epidemic worldwide for two years, many people have no immunity, and there has long been concern that it will spread more than before the new coronavirus. It's a situation. We should think that the number of cases will increase in Japan after the new year. It's not too late, so I would like you to consider getting a flu vaccine."

Year-end and New Year preparations, assuming a tight medical situation

New year's holiday in this situation.

Not only medical institutions but also pharmacies will be different from the usual system.

It is important to prepare antigen test kits and antipyretic analgesics in advance, and to check in advance whether there are medical institutions where you can receive medical care not only in the area where you live but also at your hometown or travel destination.

In order to prevent overcrowding of medical facilities and to be able to respond to people at risk of becoming seriously ill, if you have symptoms such as fever, sore throat, and malaise, you should test at home using an antigen test kit. , The Ministry of Health, Labor and Welfare is calling on people who are positive but have a low risk of becoming seriously ill to stay at home and rest.

The utilization rate of hospital beds is also increasing, and the number of cases in which it is difficult to transport by ambulance is also increasing.

Even at university hospitals in Tokyo, the beds for corona patients are full, and there are some places where emergency transport for corona and other than corona is not available.

An expert meeting of the Ministry of Health, Labor and Welfare said that the number of cases other than the new corona that were difficult to transport had already passed the peak of the ``7th wave,'' and that it was necessary to pay attention to securing an emergency medical system for the year-end and New Year holidays. increase.

No change in infection control measures to be taken

The Ministry of Health, Labor and Welfare's expert meeting calls for the completion of vaccination against the Omicron strain by the end of the year, and calls for the use of antigen test kits that can be tested by oneself in preparation for infection.

And the important thing is 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.

In addition, since the spread of the new coronavirus began, the number of infections has continued to increase rapidly throughout the country due to the increased opportunities to come into contact with people who do not usually meet during the year-end and New Year holidays. increase.

It is also important to refrain from attending year-end parties, New Year parties, or when returning home if you are worried about having cold-like symptoms.