The phase-II trial results of a potential malaria vaccine appeared in the British medical journal The Lancet showed that its effectiveness came down to 46% providing protection for 15 months from 53% for eight months in the first trial. But, as per experts from India, a malaria vaccine should provide effectiveness rate of more than 75%.
The vaccine that completed its phase-2 trials targets malaria parasite when it starts entering the bloodstream or liver cells so that infection can be controlled from attacking red blood cells and to check the progression of severe symptoms. 
In the first trial of the vaccine, 894 children aged 5-17 months from Kenya and Tanzania were involved and they were given three doses of either RTS,S/AS01E or rabies vaccine. The malaria vaccination provided 53% effectiveness for at least eight months. In the second trial, same participants were tracked for another seven months and the vaccine protected against the disease with 45.8% effectiveness for at least 15 months.
The side-effects of the vaccine found were gastroenteritis, pneumonia and febrile convulsion, but they were fewer in comparison to the rabies vaccine.
More studies are required to be conducted so to confirm the effectiveness of the vaccine among children who are HIV infected or are malnourished.
The vaccine’s last-stage trials on 16,000 children in Africa are going on, which will get completed in February. If the effectiveness of the vaccine finds apt, it could get license. In such a scenario, the vaccine would be available in 2015.