After Seoul, Busan Nursing Hospital Breakthrough Infection Emergency… Expert “The fashion situation has changed, so a booster shot is needed”

Despite high-intensity social distancing, the number of new coronavirus infections (COVID-19) has been recording four-digit numbers for 33 consecutive days. A breakthrough infection is defined as a confirmed case 2 weeks after completion of vaccination. Experts said that the vaccination rate has been sluggish since last February, when the vaccine was started, and it is the result of not quickly forming herd immunity.

On the morning of May 26, medical staff are dispensing vaccines at the Corona 19 Vaccination Center at the Jungnang Cultural Gymnasium in Seoul. News 1

According to Busan City on the 8th, the cumulative number of confirmed cases related to the nursing hospital in Gijang-gun was 48 (41 patients, 5 workers, 2 family contacts), of which 42 were found to have breakthrough infections. Except for two hospitalized patients who received the Pfizer vaccine, 35 inpatients and five workers were confirmed to have been infected after receiving the AstraZeneca (AZ) vaccine. Following two nursing hospitals and nursing facilities in Seoul, a breakthrough case of infection has also emerged in Busan, where the spread of infection is high.

According to the quarantine authorities, as of the 29th of last month, there were 1,132 (0.018%) of the estimated cases of breakthrough infection in Korea. The number of breakthrough infections per 100,000 population is 17.8, divided by vaccine: ▶ Janssen 51.4 ▶ AZ 24.3 ▶ Pfizer 7.8 ▶ Cross-vaccination 1.9. More than half of them were confirmed to have a delta mutation infection. Major mutations were found in 61.7% (150 patients) out of 243 patients with mutated virus analysis completed.

On the afternoon of the 5th, at the Pfizer Vaccine Vaccination Center for the Novel Coronavirus (COVID-19) infection in Buk-gu, Gwangju, health center medical staff vaccinate subjects. yunhap news

Experts pointed out that the delta mutation is one of the causes of recent breakthrough infections. It is pointed out that there is a limit to blocking the current delta mutation epidemic because the current COVID-19 vaccine was made with a virus that originated in Wuhan, China at the beginning of the outbreak. Professor Kim Woo-joo of the Department of Infectious Diseases at Korea University Guro Hospital said, “There is a difference between the vaccine antigen and the current delta mutant antigen. We are using a vaccine,” he said. Jeong Jae-hoon, a professor of preventive medicine at Gachon University College of Medicine, explained that, in addition to the effect of vaccines, if the spread of the mutated virus increases, the absolute number of confirmed cases increases, so naturally, the number of breakthrough infections will also increase.

Professor Kim Woo-joo was also concerned about the fact that a lot of time has passed since the first vaccinations for residents of nursing hospitals and facilities began in February or March. Professor Kim said, “Most vaccine companies say that they are effective for at least six months, but it is true that the effect gradually diminishes. The fall is also large,” he pointed out. Professor Kim said that this is why Israel, the United Kingdom, and the United States are trying to set booster shots for the elderly or chronically ill. “The completion rate of vaccination in Korea is still only 15%, so there is still a long way to go until herd immunity,” he said, worrying that breakthrough infections could continue.

A citizen receives a Pfizer vaccine at the Vaccination Center in Dongjak-gu, Seoul on the 4th. News 1

Experts agreed that booster shot vaccination is necessary in this situation. Currently, quarantine authorities are analyzing that the seriousness or fatality rate from breakthrough infection is not high due to the effect of vaccination, but on the 26th of last month, a woman in her 80s who broke through infection died. It is criticized that it is too early to be reassured. Professor Kim said, “I think booster shots will be needed in the order of immunocompromised patients such as transplant patients, chronic disease patients, and the elderly.” He added, “Because delta mutation is rampant, it is necessary to hit a booster shot with mRNA vaccines such as Pfizer and Moderna rather than AZ, which has a low preventive effect.” Professor Jeong Jae-hoon also said, “The sooner the better,” about Booster Shang. Professor Jeong said, “Since some time has passed since the AZ vaccination, I think it is necessary to inoculate the high-risk group with an mRNA-based vaccine rather than necessarily receiving the same vaccine.”

However, Ki-seok Ki-seok, a professor of respiratory medicine at Hallym University Sacred Heart Hospital, took a cautious stance. Professor Jeong said, “Those who received the first dose of AZ in February received the second dose around the end of June, so now is the time when they have the strongest immunity. There is no rush like that,” he said. Professor Jung explained that the scientific basis for the booster shot should be clearly established. In the case of this breakthrough infection in nursing hospitals and facilities, he said, “Since living in the same space for a long period of time, there may have been a structural limit that can only be penetrated once it is pierced,” he said.

Reporter Lee Woo-rim yi.woolim@joongang.co.kr