[Details] Corona vaccine Children under the age of 4 What should I do?

Public inoculation of the new corona vaccine for children from 6 months to 4 years old will start on October 24th.

vaccination of young children.

What are the effects and side effects?

What do the experts say?

We will answer any questions that parents may have.

(Science and Culture Department Reporter Reika Ikehata / As of October 21, 2022)

Q. What are the vaccines for children 6 months to 4 years old?

It is a vaccine made by the American pharmaceutical company Pfizer, and the amount of active ingredient contained in one inoculation is about 1/10 of the adult vaccine and about 1/3 of the vaccine for children aged 5 to 11 years old.

Similar to the vaccine for children aged 5 to 11, it is a vaccine based on a conventional virus, not a vaccine that also contains components based on the Omicron strain.

You can get vaccinated for free because the entire amount is covered by public funds.

Q. What is the vaccination schedule?

3 doses are required.

The second dose should be given 3 weeks after the first dose, and the third dose should be given at least 8 weeks after that.

As a general rule, you will receive a vaccination ticket from your municipality, and you will be vaccinated individually at a pediatric clinic, etc., but some local governments have set up a venue for group vaccinations.

Q. What is the country's policy?

According to the Ministry of Health, Labor and Welfare, the number of infected children is increasing and the number of severe cases is also increasing. It is a policy to make vaccinations "obligatory" even for children under the age of 4.

"Obligation to make efforts" means that parents must make efforts to ensure that their children are vaccinated.

However, there is no compulsion or penalties, and it is up to the individual and their parents to decide whether to vaccinate or not.

Q. How effective is the vaccine?

Vaccination is expected to prevent the onset of new corona.

A Pfizer clinical trial in children aged 6 months to 4 years showed that, after three doses, the results were similar to those in clinical trials in older children and adults. Antibodies were confirmed.

In addition, during the period when the Omicron strain is prevalent, more than 1,100 children aged between six months and four years old in the United States and Europe were inoculated with the vaccine and a placebo (harmless saline solution). We investigated the subsequent infection status in children who had been infected.

As a result, of the 794 people who were vaccinated, 13 were subsequently infected with the new coronavirus.

Of the 351 people who received placebo, 21 were subsequently infected (as of June 17, 2022), and the effect of preventing the onset after 3 doses was 73.2%.

There are few infected people after vaccination, and there is not enough data to analyze how much it prevents the aggravation.

However, Tetsuo Nakayama, a specially appointed professor at Kitasato University who specializes in clinical virology and is familiar with vaccines, said, "If you can prevent the onset of the disease, you can fully expect the effect of preventing the subsequent aggravation of the disease. From ages 5 to 11, who are close in age. Although there are differences between studies, it has been confirmed that the effect of suppressing the aggravation of symptoms for people of all ages ranges from 40% to 80%."

Q. What are the main side effects of vaccines?

Most of the side effects of vaccines are mild or moderate and transient, and it is said that there are no serious safety concerns.

Pfizer's clinical trial examined side effects up to one week after vaccination.

As a result, among those aged 2 to 4 years,

▽ 5.2% of those who had a fever of 38 degrees or higher at the first vaccination, 4.9% at the second time, 5.1% at the third time,

and 29.7% had malaise at the first time. , 25.7% for the 2nd dose, 24.5% for the 3rd

dose ▽ Vomiting 3.0% for the 1st dose, 3.4% for the 2nd dose, 1.6% for the 3rd

dose ▽ Diarrhea 7.7% for the 1st dose, 6.7% for the 2nd dose , and 5.1% for the third time.

Between 6 months and 1 year of age

▽ Fever of 38°C or higher at 7.2% after 1st dose, 7.4% after 2nd dose, 6.8% after 3rd

dose ▽ Loss of appetite 22.2% after 1st dose, 22.2% after 2nd dose 22.2%, 20.2% for the 3rd

dose ▽Children who were irritated and in a bad mood were 51.2% for the 1st dose, 47.4% for the 2nd dose, and 43.6% for the 3rd dose.

Akihiko Saito, a professor at Niigata University who is a director of the Japan Pediatric Society and is familiar with vaccines, said, "Although it is not possible to make a strict comparison, the frequency of adverse reactions in children aged 6 months to 4 years is lower than that in adults. It is lower or similar to children aged 12 to 15," he said.

Q. What are the serious side effects of vaccines?

As serious side effects of the new coronavirus vaccine, mainly in young men in their teens and twenties, "myocarditis" and "pericarditis," which cause inflammation of the heart muscle and membrane, have been reported very rarely.

There are not yet sufficient data on the prevalence of myocarditis and pericarditis in children aged 6 months to 4 years.

However, according to the Ministry of Health, Labor and Welfare, cases of myocarditis and pericarditis have been reported from about 600,000 children aged 6 months to 4 years who have been vaccinated with the same Pfizer vaccine by August 21 in the United States. Not.

In Japan, the rate of suspected cases of "myocarditis" and "pericarditis" in children aged 5 to 11 years who have been vaccinated is about 2 to 3 cases per 1 million doses of vaccination. It is

"Compared to men in their teens and 20s, young children develop myocarditis and pericarditis after vaccination," said Kitasato University professor Nakayama. "Most cases are mild and recover. On the other hand, the frequency of myocarditis after being infected with the new coronavirus is much higher than the frequency of myocarditis after vaccination, and it has been reported that infected children died of myocarditis. increase.

However, within a few days after receiving the vaccine, if you have trouble breathing, complain of chest pain, or other symptoms that may indicate myocarditis or pericarditis, see a doctor immediately. I want you to

Q. What are the long-term effects?

Does it affect fertility?

Pfizer's vaccine is a new type of vaccine called "mRNA (messenger RNA) vaccine".

"mRNA" is the genetic information that becomes the "blueprint" for protein synthesis, and by injecting this, a part of the virus protein is made in the cells in the body, and it is a mechanism that allows immunity such as antibodies.

According to the Ministry of Health, Labor and Welfare, this "mRNA" is decomposed in the body in a few minutes to a few days.

In addition, "mRNA" is not incorporated into DNA, which is the genetic information of humans.

In the body, there is a mechanism by which mRNA is made from DNA, but the flow of information is one-way; conversely, DNA is not made from mRNA.

For this reason, even if you inject "mRNA", it is thought that the information will not remain in the long term or be incorporated into the genetic information of sperm and eggs.

Q. What is the vaccination situation overseas?

Overseas, there are different policies regarding vaccination for children aged 6 months to 4 years.

In the United States, permission for emergency use was issued in June 2022, and the CDC = Center for Disease Control announced that ``vaccine vaccination is recommended'', and vaccination is also permitted in Canada and other countries.

Vaccination rates in each country

▽ In the United States, 8% of people aged 2 to 4 years old who have been vaccinated at least once, and 5.2% of those under 2 years old (as of October 13, 2022)

▽ At least 1 dose in Canada 6.5% of those who have been vaccinated, and 1.0% of those who have completed three doses (as of October 9, 2022).

Q.Do children need to be vaccinated even though they are less likely to become seriously ill?

According to the Japan Pediatric Society, more than 95% of children infected with the new coronavirus have mild symptoms.

However, since the Omicron strain became prevalent, the number of infected children has increased, and the number of children who have died or become seriously ill has increased accordingly.

According to the National Institute of Infectious Diseases, from January to August 2022, when the Omicron strain spread, out of 41 people under the age of 20, including children who died of the new coronavirus, 29 were able to investigate in detail. Analyzed.

As a result, 8 children aged 0, 6 aged 1 to 4, 12 aged 5 to 11, and 3 aged 12 to 19 died.

Fourteen children under the age of four died, six of whom had no underlying medical conditions.

Although there is no data on the severity of the disease only in children aged 6 months to 4 years, the Japanese Society of Intensive Care Medicine is a nationwide medical institution with hospitalization facilities for children, and from March 10 to August 15, 2022 We are investigating the symptoms and age of patients under the age of 20 (mainly high school students and younger) infected with the new coronavirus.

As a result, a total of 220 people were registered as 'moderate' or 'severe' who needed oxygen or wore a ventilator.

By age, 15% are under 1 year old, 43.6% are preschoolers over 1 year old, 32.7% are elementary school students, 4.1% are junior high school students, and 4.5% are high school students and above, and before entering elementary school. children account for about 60% of the total.

In addition, as a result of examining the detailed symptoms of people with severe symptoms, it was found that the percentage of "acute encephalopathy", which causes brain swelling and impaired consciousness, pneumonia, and convulsions, was high.

Q.Do children infected with coronavirus need to be vaccinated?

Experts recommend getting vaccinated even if you have been infected.

Professor Saito of Niigata University said, ``Even if you have been infected with the new coronavirus, if the symptoms are mild, you may not have enough immunity.In the case of the new coronavirus, immunity weakens over time. Even if you have been infected with Corona, you can get a more reliable immunity by getting a vaccine."

In addition, regarding the timing of vaccination after infection, it is said that "you can get vaccinated when the symptoms of the new corona subside and you return to your usual physical condition."

Q. Can I be vaccinated at the same time as other vaccines that I vaccinate when I was a child?

It is possible to be vaccinated at the same time as the influenza vaccine.

About other vaccines, we are to open principle, interval of inoculation for two weeks.

For example, if a one-year-old child receives the measles-rubella combined vaccine (MR vaccine) on November 1st, he or she can receive the novel coronavirus vaccine on November 15th (two weeks later) at the earliest. day of the week).

Regarding the order of priority when inoculating multiple vaccines, Professor Saito of Niigata University said, ``Since the timing of vaccination for the vaccines designated as routine vaccinations for children has already been decided, I would like them to be prioritized first. It would be better to incorporate the new corona vaccine well and inoculate it more than two weeks before the routine vaccination or more than two weeks after it."

Q. How should I think about vaccination for my child?

How should I think about vaccination for my young child?

We asked two experts.

Professor Saito

: "Children between 6 months and 4 years old are at an age where it is difficult to take measures against infection. They cannot wear masks properly, and it is difficult to wash their hands sufficiently and disinfect their hands voluntarily. Vaccination is the only active prevention that can be done.Since other measures cannot be taken, it is important to prevent the onset of the disease through vaccination and prevent the disease from becoming severe."

Specially Appointed Professor Nakayama

“By inoculating not only the new corona vaccine, but also pneumococcal and measles-rubella vaccines, children are able to live a healthy daily life. I think you should think of it in the same way.The disadvantage of vaccination is that there are side effects.On the other hand, the disadvantage of not having the vaccine is that if you get infected, you can have complications such as severe encephalopathy and myocarditis. There is also the risk of dying from the disease.