To achieve ‘70% herd immunity ‘… “In fact, 90% of the nation should be vaccinated.”

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As vaccination for the new coronavirus infection (Corona 19) approaches 5 days in the future, the focus is on how many populations need to receive the vaccine to ensure herd immunity.

According to the health authorities of the 21st, it is known that population immunity is formed only when 70% of the total population has antibodies.

In an emergency questionnaire at the National Assembly in January, Jung Eun-kyung, director of the Korea Centers for Disease Control and Prevention, said: “It is believed that about 60-70% of the entire population should acquire immunity (group immunity). “

Consequently, the government is setting a goal of forming a herd immunity by November after the first vaccination is given to 70% of the population in September, starting with workers in nursing hospitals, medical welfare facilities for the elderly and high-risk medical institutions. .

If Korea’s population is about 52 million, it is estimated that at least 36.4 million people need to be vaccinated.

Of course, this assumes that the vaccine has a 100% antiviral effect. However, in reality, the average preventive effect of the five vaccines (AstraZeneca, Janssen, Pfizer, Modena, and NovaVax) supplied nationally is around 80%.

Furthermore, children and adolescents and pregnant women under 18 years of age are excluded from the vaccination goal themselves due to a lack of clinical trial results, and there is a public opinion that they will not receive the vaccine.

◇ “It is different from achieving a vaccination rate of 70% and a group immunity of 70%” … 3 out of 10, negative for the vaccine

Kim Woo-joo, professor of infectious medicine at Daegu Guro Hospital, said on YouTube: “The ‘70% of the population ‘should not be confused with the ‘70% herd immunity.’ Even if the vaccination rate is 70%, group immunity is not formed. It means that 70% must have a protective immunity to defend against Corona 19, that is, a ‘neutralizing antibody’ “.

This is because the preventive effect of the currently developed vaccine is less than 100%.

When looking at the results of the clinical trials of five vaccines introduced in Korea, the preventive effect ranges from at least 62% to a maximum of 95%.

Regarding the preventive effect of each type of vaccine, AstraZeneca, which is the first to be supplied to Korea, is 62-70%, Janssen 66%, NovaVax 89.3%, Modena 94.1% and Pfizer 95%.

If the average preventive effect of these vaccines is calculated at 80%, it is concluded that it is possible to achieve 70% group immunity only when 46.2 million people, who are 89% of the Korean population, receive the vaccine.

Previously, the government announced that it plans to vaccinate a total of 43.55 million people for the fourth quarter of this year through the ‘Corona Vaccination Implementation Plan February 19-March’. This is approximately 84% of the total population.

Taking into account children and adolescents under 18 years of age excluded from vaccination, pregnant women and those who do not wish to be vaccinated, almost the entire population should receive the vaccine.

In fact, there are many negative opinions about vaccination.

As a result of a survey conducted by Professor Yu Myung-soon from Seoul National University Graduate School of Public Health from 5 to 7, 3 out of 10 responded that they would postpone or refuse vaccination.

Looking at the content of the survey, 26.8% of respondents said: “I want to postpone the time or order of vaccination to the next one” and 4.9% said “I will refuse vaccination.” It is estimated that 31.7% of all respondents had a negative opinion of vaccination.

This is also happening in Israel, the fastest vaccinating country in the world.

According to Professor Kim, the United States is the first in absolute quantity when looking at the cumulative dose of vaccine by country, but Israel has the highest vaccination rate per 100 people at 78%.

Professor Kim said: “In Israel, people who could get vaccinated quickly started to get vaccinated, but there were about 20% of the ‘concrete layers’ that refused to be vaccinated. I can see it.”

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◇ Expert “Pregnant women and juvenile vaccinations seem difficult … I need to rush the vaccination before the South African mutant virus spreads”

Experts believe that more than 80% and about 90% of the population should be vaccinated to form herd immunity.

Daewoo Seol, professor at Chung-Ang University College of Pharmacy, said: “Clinical data such as under 18s, pregnant women, etc. will be obtained only when 80-85% of the population is correct. , because vaccines have different preventive effects and the amount of vaccines is different. ” If you consider those who have a hard time getting vaccinated because they don’t, or those who refuse out of fear of religious beliefs or side effects, it will only be possible if they are correct. “

Professor Seol predicted that future vaccinations would be difficult because it would be difficult to proceed realistically with vaccinating children under 18 years of age and pregnant women.

“Because the vaccine was rapidly developed, few manufacturers have conducted clinical trials for pregnant women or women under 18 years of age,” he said. “In particular, in the case of the Pfizer vaccine, people with a history of allergies to avoid delays in vaccine development due to side effects in the clinic. Until the clinical trial was excluded,” he explained.

However, Professor Seol said: “If the number of people who received the vaccine increases as a result of the (government) vaccination, 70% of the immunity of the population is possible because it induces the vaccination itself.” “There should be no cases of death.” . “

Professor Seol also mentioned that there were several deaths after vaccination in Norway. “Unlike Pfizer so far, the AstraZeneca vaccine did not cause death after vaccination and had fewer serious side effects.”

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Professor Kim Woo-joo also predicted: “As is known, it is expected that 80% or more of the population, instead of 70% of the population, will need to be inoculated to achieve the intended purpose (group immunity formation)” .

“Through data from Israel (which is the leading vaccination rate), we will be able to determine what percentage of the population needs to be vaccinated in a country to form herd immunity,” he said. “We only use one vaccine, and they are testing the immunity of the population with 5 vaccines with different efficacy.”

Professor Kim emphasized that since mutant viruses have emerged that can neutralize the vaccine, it is necessary to rush vaccination before the mutant species spreads further to prevent further infection.

Professor Kim said: “If a mutant virus originating from the Republic of South Africa goes into an outbreak, the AstraZeneca vaccine that we need to use right now could be a problem because it is not effective.” You should also pay attention to ensuring a vaccine that prevents it, “he advised.

He continued: “Of 99 patients with mutant virus infections identified in Korea, 80 were from the UK, 13 were from South Africa and 6 were from Brazil. We hope that the mutant virus is not outbreaks, but the vaccine that we have secured.” It is to our advantage that there are many UK mutations that can be expected to be effective. “

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