Preparations have begun for the fourth inoculation of the new coronavirus vaccine.
Many people haven't finished the third vaccination yet, so is the fourth vaccination necessary?
Wasn't it supposed to be effective up to the third time?
I have compiled information about the 4th inoculation as to whether I should continue to hit it again in the future.
(As of March 29)
Preparations for the 4th inoculation begin ...
As of the end of March 2022, the vaccination rate in Japan exceeded 80% among the elderly who completed the third booster vaccination, but the overall rate is only about 40%.
As early as that, the government has included in the basic coping policy for the new corona measures to secure the necessary vaccines with a view to implementing the fourth vaccination.
Then, on March 25, the Ministry of Health, Labor and Welfare notified local governments nationwide to complete preparations for shipping such as printing of vaccination tickets and arrangements for the venue by the end of May.
Preparations have begun, but as of late March, the application for approval of the fourth inoculation has not been submitted in Japan, and it has not been officially decided to inoculate.
Is a fourth vaccination necessary?
I asked the expert's opinion whether the fourth vaccination is necessary.
Takaji Wakita, chairman of the expert meeting of the Ministry of Health, Labor and Welfare, said on March 23, "It has already been reported that the effect of the third vaccination decreases after a certain period of time. People with underlying diseases and the elderly It is assumed that the 4th inoculation to those who are at risk of serious illness will probably be necessary. The interval between inoculations may be shorter than the 3rd inoculation, so it is necessary to prepare and encourage in time. There is. "
In addition, Atsuo Hamada, a specially appointed professor at Tokyo Medical University who is familiar with infectious diseases, points out that if preparations for the fourth vaccination are not started from now on, problems of securing vaccines and vaccination sites may occur. ..
Specially Appointed Professor Atsuo Hamada
"The third inoculation should have started earlier. It is important to prepare early because the third inoculation did not progress easily. For many people, be aware of the fourth inoculation. I think it will be a little further, but at least in terms of administration, it is necessary to proceed early even with preparations. "
Wasn't three inoculations enough?
It has been said that the third vaccination that is currently being given is also done to regain the effect of the vaccine that has declined over time after the two vaccinations.
Shouldn't that be enough?
However, for Omicron strains, which now account for almost all of the world's new coronaviruses, the effect of the third inoculation is lower than that of the previous Delta strains, and over time. It is known that the effect will decrease.
According to data from the British health authorities, the effect of Omicron strains on preventing hospitalization compared to unvaccinated people is that Pfizer's vaccine is given twice and then Pfizer's vaccine is added. It was about 90% after 2 to 4 weeks, but dropped slightly to about 75% after 10 to 14 weeks.
With the booster vaccination of Moderna, it is 90% to 95% by 9 weeks.
On the other hand, the effect of preventing the onset was 60% to 75% 4 weeks after the 3rd vaccination when the Pfizer or Modelna vaccine was additionally vaccinated after 2 vaccinations with Pfizer, but after 15 weeks. Then it has dropped from 25% to 40%.
It has been found that the effect of reducing the risk of hospitalization due to aggravation by the third vaccination is maintained to some extent, but the effect of preventing the onset decreases relatively quickly.
Overseas that precedes the 4th inoculation The effect is
Some overseas have already been inoculating for the fourth time.
In Israel, the United Kingdom, France, etc., inoculation is given to medical workers and the elderly.
In addition, South Korea, where the number of infected people is rapidly increasing, is also starting to target people at high risk of becoming seriously ill.
The results of a study on the effects of the fourth vaccination for healthcare workers in Israel were published in the international medical journal "New England Journal of Medicine" on March 16.
Research groups such as the Israeli Ministry of Health analyzed 154 people who were vaccinated with Pfizer for the fourth time and 120 people who were vaccinated with Moderna in comparison with those who were vaccinated three times.
After the 4th inoculation, the neutralizing antibody level increased about 10 times, which was slightly higher than that after the 3rd inoculation.
While there was no difference between the Pfizer and Moderna vaccines, the suppression of the Omicron strain was only about one-tenth that of the conventional virus.
Infections, including asymptomatic infections
, were confirmed in 25.0% of those who received the 3rd dose, and 18.3% of those who received the
4th
▽ Pfizer vaccine
▽ 20.7% of those who received the Moderna vaccine. ..
As a result, the effect of preventing infection including asymptomatic by the 4th
vaccination
is 30% with the Pfizer vaccine
▽ 11% with the modelna vaccine ▽ The
effect of preventing the onset is
▽ Pfizer's vaccine is estimated to be 43%
▽ Modelna's vaccine is estimated to be 31%.
On the other hand, the rate of adverse reactions
was 78.8% for local pain,
33.2% for malaise, and
24.5% for myalgia in total for the two vaccines combined.
▽ Headache is 21.5%
▽ Fever over 37 degrees 5 minutes is 6.6%, and
many people have some symptoms, but it is said that there was no big effect.
The research group said, "Immune is complete by the third inoculation and then declines, but it is thought that it will recover by the fourth inoculation." There is a possibility that there is only a good profit. "
Pfizer analyzed this data on March 15, and found that half of people over the age of 60 were confirmed to be infected when they received the fourth dose more than four months after the third dose. , Announced that the number of people who become severely ill has decreased to a quarter.
Based on these results, Pfizer and Moderna applied to US regulators in mid-March for an emergency use authorization for the fourth dose.
Expert “4th vaccination does not need to be hurried”
Professor Masayuki Miyasaka of the Immunology Frontier Research Center, Osaka University, who specializes in immunology, expects that the effect of preventing aggravation will increase again even if the effect of preventing aggravation decreases once from Israeli data etc. regarding the fourth inoculation. It is said that it can be done.
Professor Masayuki Miyasaka
"After the 4th inoculation, the neutralizing antibody level has risen to a certain level, and I think that it is a sufficient level from the viewpoint of immunology. Also, when looking at the effect of the vaccine We should also think about "cell-mediated immunity" in which immune cells attack the virus, but Pfizer's announcement shows that it has the effect of preventing aggravation and can be expected to play a sufficient role as a vaccine.
" In addition, people with underlying diseases such as diabetes and heart disease may have a particularly weakened immunity and are likely to be the target of the fourth vaccination. Mutant virus that is more pathogenic and infectious in the future. You don't have to rush to get a fourth vaccination, but it's important to be prepared, as you'll have to prepare now. "
Be careful about the inoculation interval?
When would you give your fourth vaccination?
And do we have to do it in a hurry?
About the 4th vaccination
▽ In the UK, for people over 75 years old who are more than 6 months after the booster vaccination, elderly people living in long-term care facilities, and people with immunodeficiency over 12 years old
▽ In France, 3 from the booster vaccination For people over 80 years old who are over 80 years old
▽ In Germany, people over 70 years old who are over 3 months after the booster vaccination, residents of long-term care facilities, people with immunodeficiency over 5 years old, and people over 6 months old We recommend inoculation to medical workers.
Also
, in Israel, for people aged 60 and over, medical professionals, and people with immunodeficiency aged 18 and over, who are more than 4 months after the
booster vaccination. It is intended for people with underlying illness, inpatients and healthcare professionals.
The Ministry of Health, Labor and Welfare says that the timing of the fourth inoculation will be based on the third to six months later, and will be considered based on overseas trends.
Regarding the interval of inoculation, Professor Miyasaka of Osaka University points out that it is more effective to inoculate after a certain period of time.
Since "B cells", which are a type of immune cell and produce antibodies, are activated after the third inoculation, it is better to wait for the B cells to mature after a longer period of time for the fourth inoculation. It is highly possible that it will be possible to produce antibodies that can respond to the virus.
Professor Invitation Miyasaka
"It is not effective from the viewpoint of immunology to give the 4th inoculation in a too short period after the 3rd inoculation. Good quality antibody by inoculating at sufficient intervals. Can be done "
Do I have to repeat vaccination?
Will the vaccine need to be given more and more in the future?
Professor Miyasaka, a professor at Osaka University, points out that the response differs depending on whether our society seeks the effect of preventing infection or the effect of preventing aggravation.
Professor Invited Miyasaka
"Immune to the new coronavirus has a short duration, and it seems that the level of immunity is not very high. Like the influenza vaccine, there are some infected people, but severe cases occur. Isn't it a good strategy to control the disease? Even if vaccinated, mild infections will occur, but they will not become severe. Hopefully, once a year will not be enough. However, people at high risk of aggravation may still need additional doses a little more often. How much dose and interval should be given to get the effect while reducing side effects? I wonder if it's okay, assuming the 4th or 5th inoculation, it should be confirmed in clinical trials in Japan as well. "
Careful opinions at the Ministry of Health, Labor and Welfare subcommittee
The fourth vaccination was approved by a subcommittee of the Ministry of Health, Labor and Welfare on vaccines held on March 24th to begin preparations.
On the other hand ,
▽
"We should evaluate the effects and costs up to the third time and discuss whether the fourth time is really necessary for everyone." In
addition to the opinion that "Isn't it?"
▽
"We have to think about positioning the fourth vaccination as a public vaccination." There were a series of cautious opinions such as "We
should fully discuss gender."
▽ "It is better to have the option of quitting while preparing. "
The Ministry of Health, Labor and Welfare will continue to discuss whether to actually carry out the fourth time based on the latest data on efficacy and safety.
Now I'm preparing for the 4th time, but first the 3rd time
On the other hand, the fourth vaccination is being prepared.
Professor Hamada of Tokyo Medical University said, "I think it would be better for elderly people with a high risk of serious illness and medical professionals to do it about half a year after the third vaccination," but now it is prioritized. He emphasizes that what should be done is to raise the rate of the third vaccination to at least 50%.
Professor Hamada
"In Western Europe, deregulation has led to a slight increase in infections, but the additional vaccination rate has exceeded 50%, and even if there are infected people, there are few people who become seriously ill, so deregulation is being relaxed. It is possible. In Japan, the third vaccination rate has exceeded 30%, so in the future, even when aiming for an exit strategy to move society and the economy, from April to May. First of all, it is important to bring it to 50% or more. Take measures such as carrying out events while making good use of methods such as wearing a mask and keeping a distance from people, and returning to daily life. Is the immediate challenge. "