The respiratory syncytial virus (RSV) vaccine is designed to protect against life-threatening respiratory infections from birth through 6 months of age via maternal immunization.

SEATTLE, USA (April 29, 2026) – Maxvax Biotechnology (USA), a Seattle-based branch of Maxvax Biotechnology Co., Ltd., located in Chengdu, China, has begun a Phase 1 clinical study of a respiratory syncytial virus (RSV) vaccine candidate intended for maternal immunization. Conducted in Australia, this first-in-human study, which is evaluating a non-adjuvanted formulation of the pre-F protein, represents an important step toward developing an affordable maternal RSV vaccine.

As the #1 cause of severe respiratory illness in infants and young children worldwide, RSV is responsible for an estimated 3.6 million hospitalizations and more than 100,000 deaths annually among children under five years of age worldwide. The burden of RSV disease is greatest in young infants, with the majority of deaths occurring in low- and middle-income countries (LMICs). Nearly half of all RSV deaths are estimated to occur before six months of age, making maternal immunization an important approach for protecting infants during this period. Vaccination in pregnancy, or maternal immunization, works by enhancing a pregnant woman’s protective antibodies, which are also shared with baby, providing protection at birth and for months thereafter

Sponsored by Maxvax with funding support from the Gates Foundation, the Phase 1 study is assessing the safety and immunogenicity of Maxvax’s maternal RSV vaccine in healthy women aged 18 to 49 years, using an authorized RSV vaccine as a comparator. Enrollment has begun at clinical sites in Melbourne and Sydney, Australia. Maxvax China manufactured the clinical trial material at its facilities in Chengdu and Shanghai.

“RSV vaccines have shown great promise in reducing respiratory disease in both older adults and young infants through maternal immunization,” said Dr. Mark Alderson, Chief Scientific Officer and U.S. Site Head of Maxvax. “With our RSV vaccine for older adults currently in Phase 3, we are excited to initiate a Phase 1 safety and immunogenicity evaluation of the liquid, non-adjuvanted formulation of our maternal RSV vaccine. If the study demonstrates that the vaccine is safe, well tolerated, and induces protective immune responses, it could open the door to developing a maternal vaccine to combat respiratory infections in young infants, particularly in LMICs.”

About Maxvax

Maxvax is a global biopharmaceutical company dedicated to the research, development, manufacturing, and commercialization of innovative vaccines and novel adjuvants. Guided by the values of Integrity, Innovation, Collaboration, and Global Service, Maxvax is committed to addressing global public health challenges and delivering solutions for major infectious and chronic diseases. Powered by cutting-edge adjuvant, recombinant protein, and immune evaluation platforms, Maxvax has established a robust vaccine pipeline targeting infectious, allergic, and oncological diseases, with three vaccine candidates currently in clinical development.