Shares of CLOVER BIO-B (02197) surged more than 9% during Tuesday's morning trading session before paring gains to trade up 7.62% at HK$2.26, with turnover reaching HK$10.41 million.

The sharp uptick followed the company's September 7 announcement of encouraging preliminary results from its Phase II clinical trial in Australia evaluating SCB-1022 (RSV+hMPV) and SCB-1033 (RSV+hMPV+PIV3) in adults aged 60 to 85 years.

The trial enrolled 420 participants. Twenty-eight days post-vaccination, neutralizing antibody titers against RSV increased approximately 6- to 9-fold, while hMPV neutralizing antibodies rose 6- to 8-fold. No vaccine-related serious adverse events were reported. The company also confirmed the successful scale-up of its 2,000-liter commercial manufacturing process.

Chief Executive Officer Liang Guo stated that "these positive clinical results significantly de-risk future late-stage development" and further validated the company's proprietary Trimer-Tag platform in developing multivalent respiratory vaccines against protein-based targets.