Scientists on Tuesday kicked off a Phase III clinical trial of a malaria vaccine – the final stage in pre-approval testing – in Bagamoyo, Tanzania, Nature News reports.

The test of the RTS,S vaccine – created by GlaxoSmithKline – will include 16,000 children under the age of two in seven African countries. Researchers hope the results of the trial demonstrate that “RTS,S prevents at least half of the infants and young children who are vaccinated from developing the symptoms of malaria, and that the protection will last for several years,” Nature News writes.

If the trial proves the vaccine offers partial protection from malaria, the drug may be submitted for regulatory review by 2011 and could be on the market by 2012, according to Nature News.

If and when RTS,S becomes commercially available, the Malaria Vaccine Initiative wants to make sure the drug is affordable and has already started talks with the Global Fund to Fight AIDS, Tuberculosis and Malaria and the Global Alliance for Vaccine and Immunizations about how to keep prices for RTS,S down.

“The cost to African babies and mothers is going to be nil. That is very clear,” Christian Loucq, director of the Malaria Vaccine Initiative, said (Nayar, Nature News, 5/27).