Hepatitis E vaccine—Illuminating the barriers to use

1. Hepatitis E virus (HEV) is one of the most common causes of acute viral hepatitis globally, but the burden is underestimated.

2. There is a highly efficacious vaccine, Hecolin, which was found to be safe and efficacious in a Phase III trial, but WHO SAGE did not recommend its routine use due to the significant lack of data on disease burden and use of vaccine outside of the trial population.

3. In 2021, a series of meetings was organized among HEV experts and representatives from global and national vaccination implementation and regulatory agencies to discuss the existing barriers to the use of hepatitis E vaccine.

4. Some of the barriers identified were: the lack of the technical capacity and resources to conduct a national review process in the absence of WHO pre-qualification for a timely decision-making on use of the vaccine in outbreak settings; the lack of vaccine supply, given the low demand for HEV vaccines and the long lead time for additional production; and the lack of evidence on safety, immunogenicity in younger individuals, pregnant women, and special populations such as those immunocompromised or with chronic liver disease.

5. Some of the recommendations from the group were: further data generation from HEV epidemiologic and vaccine studies to expand clinical data and increase awareness and understanding of the burden to support decision-making; advance purchase agreements and/or establishment of a global vaccine stockpile to be available upon urgent request.