Vaccine still effective against new prevalent flu variant: Taiwan CDC

Taipei, Nov. 30 (CNA) The current flu vaccine may provide weaker protection against infection by the new K subclade of the Influenza A virus subtype H3N2, but continues to show clear effectiveness in reducing the risk of severe illness, according to Taiwan's Centers for Disease Control (CDC) on Sunday.

The new strain of the flu virus now accounts for nearly 90 percent of confirmed flu cases in Taiwan, the CDC said.

CDC spokesperson Tseng Shu-hui (曾淑慧) said that Taiwan first detected the K subclade in July, and the variant's share of H3N2 genetic sequences in Taiwan climbed quickly from 30.8 percent in July to 87.7 percent in October.

Tseng said findings from the European Centre for Disease Prevention and Control show the K subclade contains multiple genetic mutations and displays major antigenicity differences compared with the 2025-2026 Northern Hemisphere H3N2 vaccine strain.

She added that international studies indicate the influenza vaccine maintains strong performance in reducing severe illness and hospitalization risk, despite declining protection against infection.

Tseng said completing flu vaccine doses quickly remains a key measure for reducing health risks, preventing severe cases and preserving medical capacity as the K subclade continues to spread.

According to Tseng, overall flu outbreak activity in Taiwan is now at a low point and showing a steady decline, after this year's vaccination drive started in October.

Tseng warned that flu activity could rise again after the New Year period, with the next peak expected around the Lunar New Year.