Shanghai – September 09, 2026 -- Clover Biopharmaceuticals (HKEX: 02197) reported positive preliminary Phase 2 data in Australia for two combination respiratory vaccine candidates, SCB-1022 (RSV+hMPV) and SCB-1033 (RSV+hMPV+PIV3), targeting older adults aged 60-85.
Trial enrolled 420 older adults across multiple Australian sites
The randomized, observer-blinded study randomized 420 participants to receive SCB-1022, SCB-1033 or placebo. Antibody titers at 28 days post-vaccination were in line with or trended higher than prior Phase 1 results.
Neutralizing antibody responses rose 6- to 9-fold across three viral targets
RSV neutralizing antibodies increased approximately 6-9 fold, hMPV rose 6-8 fold, and PIV3 increased more than 3 fold overall, reaching roughly 5 fold in participants with low baseline PIV3 antibody levels. PIV3 PreF-specific antibodies rose up to approximately 20 fold. No drop-off in responses was observed in participants aged 75 and older compared with those aged 60-74, and adding PIV3 antigen to SCB-1033 did not reduce RSV or hMPV antibody responses versus SCB-1022.
Vaccine groups showed 62% lower respiratory infection rate versus placebo
Based on adverse-event reporting within 28 days of vaccination, respiratory tract infection rates were approximately 62% lower in the combined SCB-1022/SCB-1033 groups than in the placebo group. The trial period coincided with a significant RSV outbreak in Australia with co-circulating hMPV and PIV. No PCR sequencing of infection cases was conducted.
Safety profile shows no vaccine-related serious adverse events
Solicited local and systemic adverse events within seven days were mostly mild and transient, with fatigue, headache and injection site pain most common, lasting a mean of approximately two days across vaccine and placebo arms. Unsolicited adverse event frequency within 28 days was similar between vaccine and placebo groups. There were no vaccine-related serious adverse events, adverse events of special interest, or discontinuations due to adverse events.
Company completes 2,000-liter commercial-scale production run
Alongside the Phase 2 trial, Clover conducted 2,000-liter bioreactor scale-up production of multiple batches of Trimer-Tagged RSV, hMPV and PIV3 PreF antigen components used in SCB-1022 and SCB-1033, a step the company said de-risks future late-stage development and commercialization.
Joshua Liang, Chief Executive Officer of Clover, said the results strengthen the potential for the combination vaccines to re-vaccinate individuals who previously received approved RSV vaccines, restoring and broadening protection. Clover said it will continue evaluating mid- and late-stage development plans and potential global collaboration opportunities for the Trimer-Tag platform.