Implementation of a Randomized, Placebo-Controlled Trial of Live Attenuated Malaria Sporozoite Vaccines in an Indonesian Military Study Population

Abstract

Malaria eradication efforts prioritize safe and efficient vaccination strategies, although none with high-level efficacy against malaria infection are yet available. Among several vaccine candidates, Sanaria® PfSPZ Vaccine and Sanaria PfSPZ-CVac are, respectively, live radiation- and chemo-attenuated sporozoite vaccines designed to prevent infection with Plasmodium falciparum, the leading cause of malaria-related morbidity and mortality. We are conducting a randomized normal saline placebo-controlled trial called IDSPZV1 that will analyze the safety, tolerability, immunogenicity, and efficacy of PfSPZ Vaccine and PfSPZ-CVac administered pre-deployment to malaria-naive Indonesian soldiers assigned to temporary duties in a high malaria transmission area. We describe the manifold challenges of enrolling and immunizing 345 soldier participants at their home base in western Indonesia before their nearly 6,000-km voyage to eastern Indonesia, where they are being monitored for incident P. falciparum and Plasmodium vivax malaria cases during 9 months of exposure. The unique regulatory, ethical, and operational complexities of this trial demonstrate the importance of thorough planning, frequent communication, and close follow-up with stakeholders. Effective engagement with the military community and the ability to adapt to unanticipated events have proven key to the success of this trial.

Figure 1.

IDSPZV1 clinical trial sites in Indonesia and Plasmodium falciparum spatial distribution in 2020. Source: The Malaria Atlas Project, https://malariaatlas.org/.

Figure 2.

IDSPZV1 recruitment flow diagram.

Figure 3.

IDSPZV1 study team workload.