Abstract
Over the past few years, hepatitis type E has been increasingly recognized as an underestimated global disease burden. Populations with severe infection-related injuries or deaths include pregnant women, patients with underlying liver disease, and the elderly. Vaccines are the most effective means to prevent hepatitis type E virus (HEV) infection. However, the development of inactivated or attenuated vaccines is not feasible due to the lack of an efficient HEV cell culture system, so researchers have conducted in-depth research on recombinant vaccines. The capsid protein (pORF2), which the virion's open reading frame 2 encodes, contains almost exclusively the HEV neutralization site. Several candidate vaccines based on pORF2 have demonstrated potential for primate protection, with two being well tolerated and highly effective in preventing hepatitis type E in adults. Hecolin® (HEV 239 vaccine), the world's first hepatitis type E vaccine, was approved for marketing in China in 2012.