The first vaccine to protect African children against malaria could be available in 2017 in the best case scenario.
Although the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) has adopted a positive scientific opinion for its malaria candidate vaccine Mosquirix for use in African children aged six weeks to 17 months, its analysis of the vaccine results show that it is not as effective against the disease as was hoped.
If the vaccine does move forward, the EMA scientists and policymakers agree, it should be used only as a complement to other tools to fight malaria, such as bed nets and antimalarial drugs, not as a replacement.
The World Health Organisation will now assess how the world’s first malaria candidate vaccine RTS,S could be used alongside other tools to prevent malaria. A second WHO committee will rule on whether the vaccine meets international standards of quality, safety and efficacy.
“The problem is that the vaccine doesn’t work all that well,” said Mary Hamel, an epidemiologist at the US Centres for Disease Control and Prevention, adding, “Ultimately, it will be up to regulatory agencies in individual countries to decide whether to approve RTS,S. Assuming WHO recommends the vaccine’s use, it will be a ‘tough decision’ for countries with limited resources.”
In a large phase III trial, whose results were released this year, the vaccine reduced episodes of malaria by about one-third in young children in sub-Saharan Africa.
That, according to Dr Hamel, is under the 50 per cent efficacy expected at the beginning of the trial.
EMA in its recommendations concluded that the benefits outweigh the risks of using the vaccine in both age groups.
“The opinion is not a recommendation for use or a formal approval. It is up to countries to decide, but it paves the way for the WHO,” said EMA in its recommendations on the use of the vaccine.
“With every vaccine you hope for 100 per cent protection. The current vaccine’s protection is substantial because if your child has three cases of severe malaria a year instead of six, it will change their lives,” said Lucas Otieno, the principal investigator at the Kenya Medical Research Institute.
“RTS,S is the first generation malaria vaccine and it will be improved over time. It is the starting point in fighting malaria with a vaccine. Remember that if approved, it will be the first vaccine in history against a human parasite and, given the disease burden, RTS,S would prevent millions of cases of malaria,” said Mr Otieno.
Malaria claims nearly 600,000 lives a year, mostly children in sub-Saharan Africa.
Phase 3 trials of the RTS,S vaccine involved 16,000 children from Burkina Faso, Gabon, Ghana, Kenya, Malawi, Mozambique, Nigeria, and Tanzania.
The vaccine reduced malaria cases by 39 per cent in toddlers aged six to 17 months and 27 per cent in infants aged six to 12 weeks. Because the vaccine’s efficacy wanes with time, the trial tested three doses delivered one month apart, followed by a booster 18 months later.