Recently, clinical data from a study evaluating the immunogenicity and safety of co-administered HPV and hepatitis E vaccines were published in Frontiers in Immunology (see full text at https://doi.org/10.3389/fimmu.2026.1837539). The results showed that co-administration of the bivalent HPV vaccine Cecolin and hepatitis E vaccine Hecolin, both produced using an E. coli-derived VLP expression technology platform, elicited favorable immune responses with a good safety profile, providing new clinical evidence for simultaneous prevention of HPV and HEV infections among women of reproductive age.

This randomized, multi-center, open-label Phase IV clinical trial was conducted at four clinical study sites in Zhejiang Province, China, from October 2021 to December 2023. A total of 480 healthy women aged 18–25 years were enrolled and randomly assigned in a 1:1:1 ratio to receive co-administered HPV and HEV vaccines, HPV vaccine alone, or HEV vaccine alone, following a 0, 1, and 6-month vaccination schedule. IgG antibody levels against HPV16, HPV18, and HEV were measured at baseline and Month 7.

After completion of the full vaccination schedule, all groups achieved 100% seroconversion. In the co-administration group, the geometric mean concentrations of antibodies against HPV16, HPV18, and HEV were 433.16 IU/mL, 318.30 IU/mL, and 10.51 WU/mL, respectively. Compared with the corresponding single-vaccine groups, the GMC ratios were 0.82, 0.78, and 0.94, respectively, with the lower bounds of the 95% confidence intervals all above the predefined non-inferiority margin of 0.5. In terms of safety, most adverse reactions were Grade 1, and no vaccine-related serious adverse events were reported across all groups.

Both HPV and HEV infections represent important public health concerns for women of reproductive age. Persistent HPV infection is closely associated with cervical cancer and other HPV-related diseases, while HEV infection may lead to severe outcomes in pregnant women and adverse pregnancy outcomes. The identical 0, 1, and 6-month vaccination schedules of the HPV and hepatitis E vaccines provide a practical basis for co-administration. The study demonstrated favorable immunogenicity and safety of co-administration, which may help reduce vaccination visits and improve convenience and compliance.

This study provides new clinical evidence supporting the co-administration of HPV and hepatitis E vaccines, contributing to scientific vaccination practices and public health application of the two innovative vaccines in relevant populations. Further long-term data on immune persistence and protective effectiveness will continue to support the development of more comprehensive immunization strategies.

The study, titled Immunogenicity and safety of co-administered Escherichia coli-produced bivalent HPV-16/18 vaccine and hepatitis E vaccine, was published in Frontiers in Immunology. Conducted by research teams from the Zhejiang Provincial Center for Disease Control and Prevention, Zhejiang University School of Medicine, and relevant institutions, the study aimed to evaluate the immunogenicity and safety of co-administering the bivalent HPV vaccine and hepatitis E vaccine, produced using an E. coli-derived VLP expression technology platform, compared with administration of each vaccine alone.

Cecolin is a bivalent HPV vaccine jointly developed by IX and Xiamen University, and the first domestically developed HPV vaccine approved in China. Leveraging an E. coli-derived VLP expression technology platform, Cecolin was approved in China in 2019 and received WHO prequalification in 2021. As of December 2025, Cecolin has been approved in more than 24 countries and introduced into over 10 national immunization programmes, with more than 80 million doses distributed globally. Supported by more than 10-year long-term follow-up data, along with clinical and real-world evidence consistently accrued, Cecolin helps expand fundamental access to cervical cancer prevention.

Hecolin is a recombinant hepatitis E vaccine jointly developed by IX and Xiamen University, and the world’s first approved hepatitis E vaccine. Developed using an E. coli-derived VLP expression technology platform, Hecolin was approved in China in 2011 and is used to prevent hepatitis E virus infection. Supported by more than 10-year long-term follow-up data, Hecolin has demonstrated outstanding protective efficacy, immunogenicity, and safety. It has also been approved in markets including Pakistan and India, serving as an important tool for hepatitis E prevention and control.