<Anchor> As the

vaccination rate increases, the fear of Corona is gradually disappearing. However, two weeks after receiving the vaccine, the so-called 'breakthrough infection' cases are being confirmed one after another.

Research results have also come out that certain vaccines can be more vulnerable to such breakthrough infections. First, let's look at the report of Dong-chan Cho, medical reporter, and continue the story.

<Reporter> There

were 44 breakthrough infections in Korea that became infected with Corona two weeks after receiving the vaccine twice.

By vaccine, Pfizer had 26 and AstraZeneca had 18.

There were 3 mutations, 2 UK-alpha, 1 South African-beta, and no Indo-delta yet.

Korea does not have many breakthrough infections yet, but it is a big concern in the United States and Israel, where vaccination rates are high.

As a result of an analysis of 506 medical personnel infected by a US research team, as expected, 63.6% were the most unvaccinated, but 9.5% completed two weeks after receiving the vaccine twice.

It is assumed that the cause of breakthrough infection is mainly a mutated virus.

This is because it was confirmed that the amount of neutralizing antibodies in the blood of the two breakthrough infections was sufficient to block the existing virus.

All of them received the mRNA-based Pfizer or Moderna vaccines that were said to be the most protective in clinical trials.

Recently, an Israeli research team published a study showing that mRNA vaccines may be more vulnerable than other vaccines to the risk of breakthrough infection caused by mutations.

[Ki-Jong Hong / Editor-in-Chief of the Korean Vaccine Society: mRNA (vaccine for mutation) is not particularly effective, I think this is the more correct interpretation. Rather than the ability to actually suppress the virus itself, we need to look at how well the immunity created by the antigen works.] If you get a

vaccine, even if you are infected with a mutation, the chances of getting serious are very low.

However, countermeasures are necessary as they can infect others.

(Video editing: Soyoung Lee, VJ: Soyoung Shin)


Q. Why are the preventive effects and mutagenicity different for each vaccine?

[Cho Dong-chan/medical reporter (specialist): When you get the vaccine, you have two in your body. One is a neutralizing antibody that prevents the virus from penetrating human cells at all, which must match the virus to work, making it vulnerable to new mutations. On the other hand, the other are immune cells that kill the invading virus. Since it works after infiltration, the prevention effect itself will decrease. However, even if the virus is slightly different, it is active and relatively resistant to mutation. The degree of activation of neutralizing antibodies and immune cells is different for each vaccine, so the preventive effect and the ability to respond to mutated viruses are also different.]

Q. Which vaccine is advantageous for mutation?

[Cho Dong-chan / Medical reporter (specialist): I have a thesis. This paper reveals that the AstraZeneca vaccine will be most beneficial to the mutant virus by activating immune cells. The National Institute of Health, which has not yet approved AstraZeneca, participated as the first author. On the other hand, mRNA vaccines such as Pfizer have the advantage of being able to produce the most suitable vaccine for a mutated virus.]

Q. What is your strategy for breakthrough infection by mutation?

[Cho Dong-chan / Medical reporter (specialist): Even if the vaccines fall on the mutant virus, the preventive effect exceeds 50% of the World Health Organization's approval standard. First of all, it is of utmost importance that vaccinations are completed as planned. It is also advantageous to conduct various clinical trials including cross-inoculation. Right now, only Korea's AstraZeneca and Pfizer cross-inoculation clinical trials are in progress, but it should be expanded to other vaccines such as Janssen, Moderna, and Novavax. It is necessary to test in advance whether booster shot, which is a booster shot with a vaccine developed against mutation, is effective or safe for mutation. That way, when a foreign country decides that cross-inoculation or booster vaccination is effective for mutation, Korea can apply it quickly.]