The application for the third occupational vaccination of the new coronavirus vaccine began on the 13th.
There is concern that the Omicron strain is more infectious than the conventional mutant virus, but the vaccine used for the third inoculation is a vaccine made in response to the conventional new coronavirus that has been inoculated so far. ..
What do you think about the effect?
Concerns about lowering with Omicron strains have a certain effect
Since the Omicron strain has many mutations in the protrusion "spiked protein" on the surface of the virus, it is feared that the neutralizing antibody produced by the vaccine will be difficult to bind and the effect will be reduced.
Even so, Kiyoshu Taniguchi, director of the National Mie Hospital, a member of the government's basic coping policy subcommittee on the third inoculation with the same vaccine, is considered to have a certain effect on the Omicron strain, which is of great significance. It is said that.
"For example, even if the virus mutates and the effect of the neutralizing antibody is reduced to one-fourth, the booster vaccination enhances the immune function and quadruples the total amount of antibody. If this happens, the number of neutralizing antibodies that bind to the virus will increase. It is a merit of booster vaccination that the overall antibody level will increase. " Some things have appeared, and the effect can be expected.
The point is the long-lasting "memory" of immunity
In addition, it is important to strengthen the "memory" of immunity that "the virus is the target of attack" by the third inoculation and to make it last for a long time.
Dr. Taniguchi said, "Even if a new mutant virus appears due to overlapping mutations, it may be possible to avoid aggravation by vaccination and proper immunity, which also applies to Omicron strains. I think it is important to proceed with booster vaccination. "
The effect of preventing aggravation not only by antibodies but also by immune cells that attack viruses
In addition, Tetsuo Nakayama, a specially appointed professor at Kitasato University who is familiar with viruses and vaccines, said, "Even if there are 30 mutations in the spike protein of the protrusions on the cell surface, the total spike protein is limited to 3%, and the vaccine is not at all. It's not that it doesn't work. It's likely that the effect of controlling the infection will be slightly reduced, but the effect of preventing the aggravation will not be so reduced. "
On top of that, regarding the third inoculation, "Not only can the level of the antibody be raised, but also the immune capacity of the cells that attack the virus can be raised to a high level. There is a mutation in the virus and it may escape from the antibody, but it is wide. By inducing immunity by cells that can respond to a range of mutations and maintaining it at a high level, it is thought that it works to suppress the aggravation. "
Announcement and research that "the effect will be improved by the third inoculation"
On December 8, Pfizer, a major American pharmaceutical company, said that the effect of the vaccine against the Omicron strain was 25 times higher than that of the second vaccination by the third vaccination, and the case of the conventional virus. We announced the results of an early experiment that said it had increased to the same extent as.
When Pfizer et al. Used the serum of a person one month after the third inoculation to examine the value of the neutralizing antibody against the Omicron strain in an experiment, it was found that the value of the neutralizing antibody against the conventional virus in the person three weeks after the second inoculation of the vaccine was found. It is expected to have a high effect on Omicron strains at the same level as the value of Japanese antibody.
In addition, even in the Omicron strain, 80% of the part of the spike protein that immune cells recognize as the target of attack has not changed, and it is said that two inoculations may prevent aggravation, and a third inoculation is given. It is thought that if done, the level of immune cells will rise and it will lead to prevention of aggravation.
Meanwhile, the African Institute of Health in South Africa analyzed the effects on Omicron strains using the blood of 12 Pfizer-vaccinated individuals, and found that neutralizing antibody levels were approximately 40 minutes compared to conventional viruses. Announced that it became one of.
It is also estimated that the effect of preventing the onset is only 22.5% compared to the case of conventional viruses.
Among these, 5 out of 6 people who were vaccinated after being infected with the new coronavirus said that the effect of the neutralizing antibody was relatively high. There is a high possibility that it will enhance the work of the patient and prevent it from becoming more severe. "
The US CDC = Centers for Disease Control and Prevention reported in a weekly report on December 10 that even those who received the vaccine twice or who had completed the third dose were infected with the Omicron strain. As with previous new coronaviruses, vaccinated people are considered to have milder symptoms. "
Research is currently underway around the world on the effects of the vaccine on Omicron strains.
In the future, there is a possibility that a vaccine compatible with the Omicron strain will be required, but at this point, it is thought that the same vaccine as before will be effective.