Promising results from clinical trial of advanced malaria vaccine candidate
19 October 2011 - First results from a large-scale phase 3 clinical trial of the most advanced malaria vaccine candidate, RTS,S/AS01, announced at the Global Malaria Forum in Seattle, show a 55% reduction in the frequency of malaria episodes during the 12 months of follow-up in children 5-17 months of age at first immunization. "Malaria has never had a vaccine get this far. If licensed, it would be the very first human vaccine against a parasitic disease", said the WHO Director-General, Dr Margaret Chan, during her keynote address to participants at the 3-day Forum, a major event for malaria experts across the world.
The phase 3 trial of RTS,S includes 15 460 infants in seven sub-Saharan African countries: Burkina Faso, Gabon, Ghana, Kenya, Malawi, Mozambique, and the United Republic of Tanzania. The two age groups participating in the trials are: infants, who have received three doses of the malaria vaccine together with other routine childhood vaccines at 6, 10 and 14 weeks of age, and older children aged 5-17 months at first dose of RTS,S.
While all those involved in the trials are excited by the latest results in the 5-17 month age group, the efficacy of the population in the expected target population of 6-14 weeks is not yet known.
WHO has provided advice to the partnership responsible for the development of RTS/S — GlaxoSmithKline Biologicals and the PATH Malaria Vaccine Initiative — since the outset of the vaccine's development. The expert group advising WHO on phase 3 malaria vaccine trials, the Joint Technical Expert Group on Malaria Vaccines, has reviewed the latest results, and will review further results from the trial as they become available.
If all required public health information, including safety and efficacy data, from the trial is deemed satisfactory, a WHO recommendation for use could be possible as early as 2015. Governments in Africa often find WHO recommendations helpful for national policy-making.
Malaria is a life-threatening disease caused by parasites that are transmitted to people through the bites of infected mosquitoes. In 2009, there were an estimated 225 million cases of malaria and 781 000 deaths, mostly among children living in Africa.
Existing WHO recommended prevention, diagnosis and treatment measures have led to major reductions in malaria disease burden in recent years, with an estimated 1.1 million lives saved since 2000. Further scaling-up of these measures to achieve universal access and use is a current global health priority.