"Effectiveness of Bivalent Vaccine Confirmed Despite Multiple Variants... Low Reports of Side Effects"

[Image source=Yonhap News]

[Asia Economy Reporter Byeon Seon-jin] The Korea Disease Control and Prevention Agency (KDCA) announced on the 12th that the updated vaccines (bivalent vaccines) currently administered in Korea have been confirmed to be effective against variant viruses such as BQ.1, BN.1, and XBB.1, which are currently spreading worldwide.

The current COVID-19 situation in Korea is characterized not by a single variant but by multiple variants competing with each other. According to the KDCA, as of the first week of January (1st to 7th), the detection rates of variant viruses in Korea showed that BA.5 was the most prevalent at 34.4%, followed by BN.1 at 32.4%. BQ.1 and BQ.1.1 accounted for 7.3% and 4.8%, respectively, while XBB.1.5, which is spreading in the United States, was detected at only 0.2%, indicating low prevalence domestically.

With numerous variants coexisting, there is growing interest in whether the updated vaccines, which target BA.1 and BA.4·BA.5, are effective in preventing infection.

The KDCA cited recent research results, explaining that analysis of neutralizing antibodies in the group that received a third dose after additional vaccination with the bivalent vaccine showed more than a 2.7-fold increase in neutralizing antibodies against the currently dominant BA.4·BA.5 variants in Korea. Additionally, neutralizing antibodies against BQ.1 and BQ.1.1 increased by 2.7-fold and 2.4-fold, respectively, and XBB and XBB.1 also rose by 1.9-fold and 1.5-fold, respectively.

The KDCA stated, "The effectiveness against the BN.1 variant, which is recently increasing domestically, has also been additionally confirmed," adding, "In the group that received an additional dose with the bivalent vaccine, a 4.4-fold increase in neutralizing antibodies was observed compared to the group that completed the third dose with the monovalent vaccine."

The adverse event reporting rate after vaccination with the bivalent vaccine was 0.35 cases per 1,000 doses, which was lower than the reporting rate after monovalent vaccine vaccination (3.72 cases). For the high-risk group aged 60 and over, the adverse event reporting rate was 0.33 cases, which is lower than the overall average.

Ji Young-mi, Commissioner of the KDCA, said, "The vaccination effectiveness of the bivalent vaccine against the various emerging variant viruses has been confirmed through diverse domestic and international studies and laboratory analyses," and she urged, "To ensure a safe winter, those aged 60 and over who are at high risk of severe illness from COVID-19 infection, as well as residents and workers in infection-vulnerable facilities such as nursing hospitals and nursing homes, should definitely participate in additional vaccination."