Joe Cohen, co-inventor of malarial vaccine and GlaxoSmithKline researcher addresses a press conference on November 3, 2009 on the sidelines of the ongoing Multilateral Interventions on Malaria, MIM-PAMC conference in the Kenyan capital, Nairobi. The most clinically advanced Malaria vaccine known as RTS,S so far should be ready for use in three to five years after phase three trials began in May and is targeted to be atleast 50 percent effective against the severe form of Malaria according to Cohen.