A Phase 1, Double-Blinded, Placebo-Controlled Clinical Trial to Evaluate the Safety and Immunogenicity of HEV-239 (Hecolin) Vaccine in Healthy US Adults.

BACKGROUND

Establishing the safety and immunogenicity of a hepatitis E virus vaccine in multiple populations could facilitate broader access and prevent maternal and infant mortality.

METHODS

We conducted a phase 1, randomized, double-blinded, placebo-controlled (4:1 vaccine to placebo) trial of 30 µg HEV-239 (Hecolin, Xiamen Innovax Biotech Company Limited, China) administered intramuscularly in healthy US adults aged 18-45 years. Participants were vaccinated on days 1, 29, and 180. Participants reported solicited local and systemic reactions for 7 days following vaccination and were followed through 12 months after enrollment for safety and immunogenicity (IgG, IgM).

RESULTS

Solicited local and systemic reactions between treatment and placebo group were similar and overall mild. No participants experienced serious adverse events related to HEV-239. All participants receiving HEV-239 seroconverted at 1 month following the first dose and remained seropositive throughout the study. HEV-239 elicited a robust hepatitis E IgG response that peaked 1 month following the second dose (geometric mean concentration [GMC], 6.16; 95% confidence interval [CI], 4.40-8.63), was boosted with the third dose (GMC, 11.50; 95% CI, 7.90-16.75) and persisted through 6 months.

CONCLUSIONS

HEV-239 is safe and elicits a durable immune response through at least 6 months after the third dose in healthy US adults.

CLINICAL TRIALS REGISTRATION

NCT03827395.