The Malaria Vaccine that will change millions of lives in Africa
Katie Jones discusses the recent recommendation by the WHO to roll-out a Malaria Vaccine, how this vaccine will work, how Malaria initially causes disease and what impact this vaccine will have on global health particularly in Africa.
Malaria is a parasitic disease that kills half a million people (most of whom are young children) every year, almost entirely in Africa. Scientists have spent the last 100 years trying to create an effective vaccine against the disease. Finally in early October 2021, the World Health Organisation recommended the widespread use of a vaccine in children across sub-Saharan Africa.
Malaria kills half a million people (most of whom are children every year)
A vaccine against malaria has been difficult to develop as the disease has a complicated life cycle. The disease is transmitted between mosquitos and humans. When an infected mosquito bites a person, malaria sporozoites (free swimming spores) infect the liver. Here the disease matures into a form (schizonts) that invades red blood cells causing them to burst. This leads to anaemia and, when untreated, death. The life cycle is complete when an uninfected mosquito bites an infected person. The new vaccine, called RTS,S targets the first stage of this life cycle. A vaccinated person develops a high level of anti-bodies that target the sporozoites with the aim of preventing them from getting to the liver. There is also evidence that the vaccine generates specific white blood cells which can also target to sporozoites. The vaccine will be provided in four doses in children from five months old.
There are five species of malaria that infect humans consistently. The RTS,S vaccine primarily targets the deadliest of these, P. falciparum, and it is unlikely to work against other species of malaria. In trials, the vaccine was found to cause a 30 percent reduction in severe malaria cases. Beginning in 2019, the pilot scheme vaccinated more than 800,000 children in Ghana, Kenya, and Malawi. There were further difficulties in the pilot scheme caused by COVID-19. The pandemic made it harder to reach already hard to access communities and the significant rise in vaccine misinformation increased vaccine hesitancy in some communities. However, these challenges were overcome, and the vaccine was found to increase equity of preventative measures by reaching communities who lacked over resources such as bed nets.
The vaccine was found to cause a 30 percent reduction in deadly severe malaria cases.
Speaking to the Guardian, Professor Chris Drakeley said that political will “is the biggest driving factor” in the development of measures against disease. There has not been local transmission of malaria in the EU since the 1970s so the issue feels distant. Professor Drakeley speculates that if malaria remained a problem in the UK, work on a vaccine would have progressed more quickly.
The RTS,S vaccine will not mean the end of malaria. However, it is another tool in the box. When used in conjunction with bed nets, early detection and medication, it will significantly reduce the number of children who die from malaria each year. It is vital that the vaccine remains easy to access. Currently malaria can financially debilitate families. There is hope the vaccine will help prevent the decision between death and financial ruin for parents.
Other malaria vaccines remain in development. These target the disease at different parts of the life cycle and there is the possibility they could be used in combination with the RTS,S vaccine to attack the disease at all stages.