After extensive trials, results for the new malaria vaccine, known as RTS.S, have proved highly encouraging. Over the last 18 months, the vaccine has been trialled among 15,500 children across seven countries. The results showed that among children aged 5–17 months, there was a 46% reduction in the risk of youngsters developing clinical malaria compared with those who had been unvaccinated. For infants aged 6–12 weeks cases of malaria were reduced by around 25%.
The parasites which cause malaria are transmitted to humans by the bite of infected female mosquitoes. Globally, more than 3 billion people are at risk of catching malaria. Each year, there are more than 200 million cases of the disease, resulting in around 660,000 deaths. Populations living in sub-Saharan Africa are at the highest risk; approximately 80% of all cases and 90% of malaria-related deaths occur in the African region, with children under five years and pregnant women most severely affected.
Over the last decade, the World Health Organisation (WHO) and other international bodies have overseen a rapid expansion of malaria-reducing interventions across sub-Saharan Africa, such as insecticide-treated nets and anti-malarial drugs. This concerted effort is estimated to have saved more than 1 million people. However, in recent years, progress to spread interventions has slowed. Health experts have also been concerned by a worrying rise in mosquito resistance to insecticides and anti-malarial drug combinations. The positive results of the vaccine trials are therefore most welcome. If approved in 2014, the new vaccine will be an important additional tool in the battle to reduce deaths caused by malaria.
A non-profit-making vaccine
Thanks to additional funding from the Bill and Melinda Gates Foundation, the vaccine will be produced by the non-profit-making PATH Malaria Vaccine Initiative. (The drug manufacturer will add 5% to the cost price to raise funds for further research and development work on tropical diseases.) It is hoped that if it is approved by the European Medicines Agency next year, the vaccine could go into production as early as 2015.
The vaccine should provide protection for around 18 months, though its efficacy does drop over time. Nevertheless, if just half of vaccinated children are given resistance for more than a year, many thousands of lives could be saved. The vaccine could also reduce the number of cases of serious illness from malaria, which can damage a child’s long-term development. And the savings to health systems could be appreciable. Speaking to the Guardian, the vice president of PATH said that even with the limited efficacy of the vaccine, it has the potential to have a “significant public health impact”.