First bovine vaccine to prevent human schistosomiasis - a cluster randomised Phase 3 clinical trial. (April 2023)

• Record Type: Journal Article
• Authors: Ross, Allen G.; Harn, Donald A.; Chy, Delia; Inobaya, Marianette; Guevarra, Jerric R.; Shollenberger, Lisa; Li, Yuesheng; McManus, Donald P.; Gray, Darren J.; Williams, Gail M.
• Is Part Of: International journal of infectious diseases. Volume 129(2023)
• Page Start: 110
• Page End: 117
• Publication Date: 2023-04
• Subjects: Schistosomiasis -- Zoonosis -- Bovines -- Vaccination -- Control -- One Health; Communicable diseases -- Periodicals; Communicable Diseases -- Periodicals; Communicable diseases; Periodicals; Electronic journals; 616.9
• DOI: 10.1016/j.ijid.2023.01.037
• Languages: English
• ISSNs: 1201-9712

Abstract

Highlights: Schistosomiasis is a neglected tropical parasitic disease caused by the blood fluke Schistosoma . Praziquantel is the mainstay of treatment and community-based control, but it is failing in some regions. Schistosomiasis control in Asia is complicated by the zoonotic nature of the disease. Vaccination of bovines has been proposed as a tool to assist in long-term control. We report the results of a cluster randomized control trial using a SjCTPI-Hsp70 bovine vaccine. Abstract: Objective: Schistosomiasis is a neglected tropical parasitic disease caused by blood flukes of the genus Schistosoma. Schistosoma japonicum is zoonotic in China, the Philippines, and Indonesia, with bovines acting as major reservoirs of human infection. The primary objective of the trial was to examine the impact of a combination of human mass chemotherapy, snail control through mollusciciding, and SjCTPI bovine vaccination on the rate of human infection. Methods: A 5-year phase IIIa cluster randomized control trial was conducted among 18 schistosomiasis-endemic villages comprising 18, 221 residents in Northern Samar, The Philippines. Results: Overall, bovine vaccination resulted in a statistically significant decrease in human infection (relative risk [RR] = 0.75; 95% confidence interval [CI] = 0.69 to 0.82) across all trial follow-ups. The best outcome of the trial was when bovine vaccination was combined with snail mollusciciding. This combination resulted in a 31% reduction (RR = 0.69; 95% CI = 0.61 to 0.78) in human infection. Conclusion: This is the first trial to demonstrate the effectiveness of a bovine vaccine for schistosomiasis in reducing human schistosome infection. The trial is registered with Australian New Zealand Clinical Trials Registry (ACTRN12619001048178).