By David Kipkorir
The World Health Organisation (WHO)recently advised that the RTS,S/AS01 vaccine, also known as Mosquirix, should be used among children in sub-Saharan Africa and other regions with moderate to high rates of Plasmodium falciparum transmission.
The historic malaria vaccine was developed by GlaxoSmithKline (London, England) over the last 30 years in partnership with PATH (WA, USA), after a 100-year endeavour. The ongoing Malaria Vaccine Implementation Programme and rollout of the vaccine is expected to change African lives forever, according to health experts.
The approval follows the successful pilot immunisation programmes in Ghana, Kenya and Malawi where 2.3 million doses of Mosquirix have been administered to infants in a large-scale pilot programme coordinated by the WHO. RTS,S is the world’s first malaria vaccine shown to provide partial protection against malaria in young children.
The vaccine will be provided to young children through national immunization programs in parts of three sub-Saharan African countries. Malaria is one of the most significant infectious diseases worldwide, often affecting vulnerable groups the most including infants, children and people in poverty who cannot afford medical treatment.
For many years, Africa has carried the highest share of the global malaria burden; in 2019, the WHO African Region was home to 94 per cent of global malaria cases and deaths. Therefore, this breakthrough, for many Africans, is game-changing news.
The P. falciparum malaria parasite is spread to humans via infected female Anopheles mosquitoes biting the skin. The subsequent malaria infection is an acute febrile illness Vector control has remained the most prominent prevention method to reduce malaria transmission, but with the rollout of the RTS,S vaccine, the world is hopeful for a cure.
“We have long hoped for an effective malaria vaccine and now for the first time, we have such a vaccine recommended for widespread use. The recommendation offers a glimmer of hope for the continent which shoulders the heaviest burden of the disease and we expect many more African children to be protected from malaria and grow into healthy adults,” explained Dr Matshidiso Moeti, WHO Regional Director for Africa.
RTS,S prevented approximately 4 in 10 malaria cases when tested in children aged over 5 months who received four doses of the vaccine during large-scale clinical trials in selected areas of Ghana, Kenya and Malawi over 4 years.
The ongoing pilot programme will continue to moderate the vaccine’s impact long-term. Resistance to antimalarial medicines such chloroquine and sulfadoxine-pyrimethamine in the past makes the new vaccine even more remarkable.
The vaccine was created in 1987 by scientists working in GSK laboratories. In early 2001, GSK and PATH—with support from the Bill & Melinda Gates Foundation—entered into a partnership to develop the vaccine for infants and young children living in malaria-endemic regions in sub-Saharan Africa. Early clinical development was conducted in collaboration with the Walter Reed Army Institute for Research. Its efficacy was established in a Phase 3 trial that concluded in 2014.
In January 2016, WHO endorsed the joint recommendation of two advisory bodies and recommended pilot implementation of the vaccine in three to five settings in sub-Saharan Africa. In response to that recommendation, a country-led, WHO coordinated Malaria Vaccine Implementation Programme (MVIP) was designed to understand the operational issues in using the vaccine in the context of other malaria interventions.
The MVIP specifically assessed the feasibility of administering the required four doses of the vaccine in children. Financing for the MVIP has been mobilized through an unprecedented collaboration among three global health funding bodies: Gavi, the Vaccine Alliance; the Global Fund to Fight AIDS, Tuberculosis and Malaria; and Unitaid.
Additionally, WHO, PATH, and GSK are providing in-kind contributions, which include GSK’s donation of the vaccine for use in the MVIP. However, additional resources will be needed to bring this vaccine into wide-scale use. RTS,S aims to trigger the immune system to defend against the first stages of malaria when the Plasmodium falciparum parasite enters the human host’s bloodstream through a mosquito bite and infects liver cells.
The vaccine is designed to prevent the parasite from infecting the liver, where it can mature, multiply, reenter the bloodstream, and infect red blood cells, which can lead to disease symptoms.
