[COVID-19 Resurgence] "Existing Vaccines Ineffective" ... Will the '4th Dose' Be Administered?

Rapid Virus Mutation... Already Reached 'BA.5'
Improved Vaccines Are Being Developed but Can't Keep Up

Fast Spread Despite High Vaccination Rates Increases Distrust
Experts Say "High-Risk Groups Should Get Existing Vaccines for Benefit"

Prime Minister Han Duck-soo received the fourth dose of the COVID-19 vaccine on the afternoon of the 8th at the Jongno-gu Public Health Center in Seoul. [Image source=Yonhap News]

[Asia Economy Reporter Lee Chun-hee] As the government officially declares the resurgence of COVID-19, attention is focused on whether additional vaccinations will be administered. However, with the virus rapidly mutating, criticism is mounting that the preventive effects of existing vaccines are not clear, strengthening the expectation that vaccinations will be prioritized for high-risk groups such as the elderly rather than for the entire population.

According to health authorities on the 11th, the government declared a shift to a COVID-19 spread phase as of the 8th and has begun preparations for high-intensity quarantine measures. The fastest mutation speed of the virus is pointed out as the main cause of the resurgence. Following BA.2, known as the "Stealth Omicron," which was more infectious than the original Omicron BA.1, the BA.5 variant, known to have even stronger transmissibility, is gaining ground domestically. The detection rate of BA.5, which was 10.4% in the fourth week of June (June 19?25), has surged to 28.2% in just one week. If this situation continues, it is expected to soon become the dominant strain.

In response, the government is considering additional vaccinations as one of the main quarantine measures. Since most of the vaccines developed so far are based on the original "Wuhan virus," even if the infection prevention effect against BA.5 is significantly reduced, it is emphasized that the vaccines still help lower the risk of severe illness and death.

Furthermore, about 100 million doses of vaccines scheduled for introduction in the second half of the year will be switched to updated vaccines developed to respond to Omicron. Pfizer, Moderna, and Novavax are currently developing vaccines targeting the Omicron variant. Pfizer reported that its bivalent vaccine under development increased neutralizing antibody titers against BA.1 by 9 to 11 times. These vaccines are expected to be released within the second half of this year.

'COVID-19 Strikes Again'

Even with Updated Vaccines... Low Effectiveness Against Latest Variants and Growing Distrust

[Image source=Yonhap News]

However, these vaccines also raise concerns due to their low preventive effect against BA.4 and BA.5. Both Pfizer and Moderna booster vaccines are not ineffective against BA.4 and BA.5, but their efficacy is reported to be about three times lower compared to the prevention effect against BA.1.

There is also worry that vaccination participation will be low due to widespread distrust of vaccines, even if updated vaccines are introduced. The domestic vaccination rate for the second dose is 87.0%, showing high initial acceptance, but since the third dose, the vaccination rate has increased by only 1% over the past three months, maintaining a low rate of 65%.

Amid ongoing complaints about adverse reactions after vaccination, the rapid spread of the Omicron variant, which has a high ability to evade existing vaccines, has led to a cumulative 18.51 million confirmed cases, increasing distrust in the infection prevention effect. Professor Kim Woo-joo of the Department of Infectious Diseases at Korea University Guro Hospital said, "Distrust and avoidance of vaccines have increased," and urged, "It is important for health authorities to increase communication and expand compensation for damages to restore trust in vaccines."

Experts emphasize that despite this, a fourth dose should be administered to high-risk groups who have a high possibility of severe illness upon infection. Professor Baek Soon-young, Emeritus Professor at the Catholic University Medical School, said, "Since existing vaccines have almost no preventive effect against BA.4 and BA.5, there is no point in receiving a fourth dose unless you are in a high-risk group," but added, "For the elderly or patients with weakened immune systems due to underlying diseases, their ability to produce antibodies is low, so even the current vaccines are more beneficial."