Hepatitis E Vaccine (Hecolin/HEV 239)
The only licensed hepatitis E vaccine worldwide is HEV 239 (Hecolin), which is currently approved only in China and not available in most other countries including the United States and Europe. 1
Vaccine Efficacy and Characteristics
Hecolin demonstrates 97% efficacy in preventing symptomatic acute hepatitis E, with long-term efficacy of 86.6% (95% CI: 73.0-94.1) maintained at 10 years follow-up. 1, 2
The vaccine is based on a recombinant protein containing 239 amino acids of HEV ORF2 protein (aa 368-606) derived from HEV genotype 1. 1
It provides cross-genotype protection, having demonstrated efficacy against both HEV genotype 1 and genotype 4 infections. 1
The vaccine does not provide sterilizing immunity—subclinical infections can still occur despite vaccination. 1
Current Limitations and Availability
Hecolin is licensed only in China (approved by CFDA in 2012) and is not available for use in the United States, Europe, or most other countries. 3
Efforts are underway to obtain WHO prequalification for emergency use settings, particularly for outbreak prevention in African refugee camps and similar high-risk environments. 1
Unresolved Safety and Efficacy Questions
The following populations lack definitive safety and efficacy data for HEV vaccination: 1
- Immunocompromised patients (including transplant recipients and those on immunosuppressive therapy)
- Patients with chronic liver disease or end-stage liver disease awaiting transplantation
- Pregnant women (though preliminary data suggest safety) 1
- Efficacy against HEV genotype 3 (the predominant genotype in Europe and North America) remains to be determined 1
Alternative Prevention Strategies
Since HEV vaccination is unavailable outside China, high-risk populations must rely on food safety measures: 1
Immunocompromised individuals and those with chronic liver disease should avoid consumption of undercooked pork, wild boar, venison, and shellfish. 1
Meat should be thoroughly cooked to internal temperatures of at least 70°C (158°F). 1
These dietary precautions are particularly critical for patients at risk of severe acute hepatitis or chronic HEV infection (immunosuppressed patients, pregnant women, those with pre-existing liver disease). 1, 4
Clinical Context
There are currently no FDA-approved treatments for hepatitis E infection, making prevention through dietary measures the primary strategy in countries without vaccine access. 4 Ribavirin is used off-label to reduce viral load in severe cases, but this is not an approved indication. 4