A partnership with pharmaceutical company GlaxoSmithKline (GSK), PATH’s Malaria Vaccine Initiative, and research centers across Africa has achieved a significant scientific milestone in the quest to develop a malaria vaccine. GSK’s RTS,S (Mosquirix™) has received a positive scientific opinion from European regulators, bringing it one critical step closer to possible implementation.
RTS,S is the first vaccine against the malaria parasite that has reached this far. This positive opinion is an important step in the process of developing a vaccine for use alongside existing malaria prevention tools, such as bednets, drugs, and indoor residual spraying. The opinion underscores that it is technically possible to develop malaria vaccines, although a number of steps remain before one might be available for use. It also validates the continued investment in next-generation vaccines.
The need for new tools
Despite incredible progress over the last decade, this mosquito-borne disease remains a major public health problem:
- Nearly half the world’s population is at risk of contracting malaria.
- The World Health Organization (WHO) estimates that 198 million cases and 584,000 deaths occur annually.
- The majority of these deaths are among children in sub-Saharan Africa younger than age five.
In addition to the need for robust, predictable, and sustained financing to accelerate the fight against malaria, we need new interventions that address the emergence of resistance to the drugs and insecticides that are used in malaria programs today to help ensure the gains we’ve made are not lost.
RTS,S is the malaria vaccine candidate most advanced in development globally. Final results from a large-scale Phase 3 efficacy and safety trial, published in the Lancet earlier this year, showed that RTS,S helped protect children and infants from clinical malaria for at least three years. In all, clinical trials in the Phase 3 program involved more than 16,000 infants and young children in eight African countries.
Where to from here?
This scientific opinion by European regulators paves the way for WHO to further assess how the vaccine may be implemented in national immunization programs. The organization could issue a policy recommendation as soon as the end of the year. This recommendation would provide additional critical guidance to countries about where, how and under what conditions the vaccine may be used.
Other key steps in the policy and regulatory process include prequalification (another WHO process to ensure that the manufacture of medical products, such as vaccines, meets global standards for quality, safety, and efficacy), procurement and financing decisions by key entities like UNICEF and Gavi, the Vaccine Alliance, and eventually, review by individual African countries to make decisions about whether to license the vaccine and make it available for use within national immunization programs.
While there is still further to go for RTS,S and licensure is not guaranteed, Dr. Kwaku Poku Asante, a principal investigator at the Phase 3 clinical trial site in Kintampo, Ghana, is finding cause to celebrate.
“On behalf of the network of clinical trial sites that provided the data that underpins the opinion, I can say that we are all very proud of how far this vaccine candidate has come,” he said. “While the story is far from over, we have already made history, demonstrating once again the capacity of African research scientists to conduct world-class research here at home and the willingness of African families to contribute to the well-being of their communities and nations.”
To learn more about this milestone, please read the announcement.
- Dr. David Kaslow is vice president of Essential Medicines and director of the Center for Vaccine Innovation and Access at PATH.