This week, in accordance with World Malaria Day (April 25) and World Immunization Week, the World Health Organization (WHO) announced a real-world pilot study that will evaluate the effectiveness of GlaxoSmithKline’s (GSK’s) Mosquirix (RTS,S/AS01) in Ghana, Kenya, and Malawi. While this announcement represents a key milestone in the quest to develop a vaccine against malaria, it is also an opportunity to acknowledge the inherent limitations of vaccines, which are by no means a magic bullet, in combatting this and other vector-borne infectious diseases.
Supported by a close partnership between pharmaceutical giant GSK and the PATH Malaria Vaccine Initiative (MVI), Mosquirix is the result of decades of malaria vaccine R&D. A randomized, double-blind, Phase III study, completed in 2014 and enrolling more than 15,000 children across 11 African countries, demonstrated the vaccine’s modest potential in curtailing malaria, which resulted in over 400,000 deaths out of 200 million new cases in 2015, according to the WHO.
Set to begin in 2018, the pilot study of Mosquirix will include more than 750,000 children across Ghana, Kenya, and Malawi, and will seek to build upon previously collected clinical evidence by examining the feasibility of administering a four-dose series of the vaccine in a real-life setting, and to confirm its safety. Administering a four-dose vaccine in resource-poor nations will be challenging, so the outcome of this study will likely determine the future clinical and commercial viability of Mosquirix.
Regardless of how Mosquirix performs in this pivotal pilot study, it is still only a single piece of a larger disease management puzzle. Specifically, GlobalData does not see vaccination alone as a viable long-term solution for combatting malaria and other arthropod-borne diseases; rather, immunization must be leveraged alongside vector control strategies, national and international surveillance programs, and public awareness campaigns as part of integrated disease prevention and control initiatives.
Renewed vector control efforts – featuring both established (mosquito nets, insecticides) and emerging (microbiological, genetic) techniques – will be especially important to curtailing future disease transmission, and the development of novel treatment options to support currently available artemisinin-based combination therapy (ACT) also stands to play a critical role in further reducing the global burden of malaria, particularly the emerging drug-resistant strains of the parasite.
Ultimately, the biomedical research and public health communities should applaud the impressive progress made in combatting malaria over the past two decades. The eventual availability of a safe and effective vaccine will help to maintain this positive momentum towards malaria’s eradication, but only if its inherent limitations are properly recognized and accounted for by public health stakeholders.