W HEN IT COMES to covid-19 vaccines, poor countries in Africa have been stuck at the back of the queue. However, the continent’s long wait for another immunological miracle appears to be drawing to a close. Later this year, the world’s first malaria vaccine is scheduled for a roll-out. Although the current version leaves much to be desired—it requires four doses, is hard to manufacture at scale and reduces severe infections by a mere 30%—better alternatives may be on the way. A jab developed by scientists at Oxford has shown 77% effectiveness. If clinical trials go well, they aim to apply for pre-qualification from the World Health Organisation in September. Production at a rate of up to 200m doses per year could follow swiftly.
Malaria has proved to be a stubborn adversary. In mosquito-rich environments, it is 5-20 times more contagious than the Omicron variant of SARS-CoV-2. The disease was once endemic across most of the world, sweeping through the Americas in the 1600s and reaching as far north as Russia’s Arctic coast and as far east as Japan.
Past efforts to defeat malaria using vaccines have failed, largely because the life cycle of the parasite that causes it has 12 stages. Each presents a different target. Instead, rich countries in cool regions have eradicated the disease by attacking the mosquitoes that spread it, both by spraying insecticides and by destroying breeding grounds. Poorer, tropical countries have fared worse. In 2020 malaria killed 627,000 people, of whom 96% lived in Africa.
New vaccines are just one element of a three-pronged strategy to vanquish malaria. Some tried-and-true tools, like installing insecticide-impregnated bed nets and distributing therapeutic drugs, can still reach more people. Another scientific advance could prove even more valuable than vaccines: genetically modified mosquitoes that cannot reproduce sustainably, which could cause the insects that spread the disease to die out. Such “gene drives” could damage ecosystems, and a regulatory process needs to be set up before they can be approved. But big donors like the Gates Foundation support them. Modellers at the London School of Hygiene and Tropical Medicine reckon that, with enough resources, by 2030 these tactics could jointly cut deaths caused by malaria by 75%.
Partly because Africa’s population is growing so fast, when projected into the future such gains would have a remarkable impact. By 2034 the annual number of deaths averted would exceed the current yearly toll from breast cancer. In total, 20m lives would be saved during the next three decades—the same number as The Economist’s estimate of the global increase in deaths during the covid-19 pandemic. And measured in years of life, this effect would dwarf covid’s. Whereas covid mainly kills the elderly, around 80% of those felled by malaria are aged five or younger.
The economic benefits are nearly as impressive. On average, adults who catch malaria lose three days of work. Cutting the number of cases by 75% would yield 14bn extra workdays over two decades, the equivalent of the current annual labour supply of Nigeria. Productivity might also improve, since non-fatal cases of malaria in children can stunt growth and hinder cognitive development, in part by inducing comas. A hidden factor holding back economic growth in Africa may be the lasting impact of the disease on survivors—call it “long malaria”. ■
Sources: Malaria Atlas Project; Our World in Data; UN; WHO; World Bank; The Economist