Safety, immune lot-to-lot consistency and non-inferiority of a fully liquid pentavalent DTwP-HepB-Hib vaccine: Results from Phase III licensure study of Shan5™

patients and those on immuno-suppression. There are four known genotypes of HEV. The most recent candidate vaccines have been two recombinant HEV vaccines. The first of these vaccines was based on a 56-kDa baculovirus-expressed ORF2 protein produced in Spodoptera frugiperda cells, developed at the National Institutes of Health, later licensed to GlaxoSmithKline. A phase II clinical trial was conducted in 1,794 young male military recruits in Nepal who received three doses 20 g of the alum-adjuvanted vaccine or placebo. Vaccinees were followed up to 2.2 years. The vaccine showed a 95% efficacy after the third dose. This vaccine study was limited by the fact that it was tested on almost exclusively young males, it did not measure the HEV infection rate and that antibody titers declined by the end of the study. The second vaccine was developed by researchers at Xiamen University in China, using a new recombinant HEV protein expressed in Escherichia coli. This vaccine, HEV 239 (Hecolin), was tested in a randomized, controlled trial involving 112,604 healthy participants aged between 16-65 years in Jiangsu Province, where HEV genotypes 3 and 4 are more prevalent. In those who received all three doses, 87% maintained antibodies and remained protected against HEV for up to 4.5 years. Its efficacy against HEV genotypes 1 and 2, in pregnant women and those younger than 16 years and older than 65 years are yet to be assessed. The vaccine is licensed for use in China. Though not yet prequalified by the WHO, the WHO is ready to assist national health authorities and regulators in a rapid assessment of this vaccine. Today, the real challenge will be to get an HEV vaccine to those who need it the most, at an affordable price.