We conducted a large phase 4, double-blind, cluster-randomised trial in 67 villages in Matlab, Bangladesh, and hereby share some of our results. Between 2017 and2021, 19 460 participants were randomised to receive HEV239, a recombinant hepatitis E virus (HEV) vaccine or a control vaccine (Hepa-B, a hepatitis B vaccine). Both groups received three doses of the vaccine at 0, 1, and 6 months, and were extensively followed for two years after the last dose to detect pregnancy, monitor the pregnancy outcome and to detect the HEV infection in both the pregnant and non-pregnant population.
HEV was not detected among pregnant women, but six HBV recipients experienced HEV in the non-pregnant population. Solicited adverse events were mild and HEV239 was well tolerated. Pain at injection site was the most common local reaction, observed at similar rate for both HEV239 and HBV vaccines. No serious adverse events were deemed to be vaccine related.
Furthermore, among pregnant participants, the HEV239 group exhibited a higher risk of miscarriage (5·7%) compared with the control group (3·9%), irrespective of the timing of vaccine in relation to pregnancy onset. This observation was further investigated in a concurrently published article by Asma Aziz and colleagues, which confirmed that HEV239 was linked to an increased risk of miscarriage when administered shortly before or during pregnancy. More details can be found in the open access article online:
Safety and effectiveness of a recombinant hepatitis E vaccine in women of childbearing age in rural Bangladesh: a phase 4, double-blind, cluster-randomised, controlled trial. Zaman K, Julin CH, Aziz AB, Stene-Johansen K, Yunus M, Qadri F, Gurley ES, Sandbu S, Øverbø J, Dembinski JL, Laake I, Bhuiyan TR, Rahman M, Haque W, Khanam M, Clemens JD, Dudman S. Lancet Glob Health. 2024 Aug;12(8):e1288-e1299. doi: 10.1016/S2214-109X(24)00192-X. PMID: 39030060
https://www.thelancet.com/journals/langlo/article/PIIS2214-109X(24)00192-X/fulltext
