Oxford’s New Anti-Malaria Vaccine
Generally, any vaccine generates immunity via two ways, one by generating antibodies and two by generating immunity response using T cells. The anti-malaria vaccine uses the latter approach to prevent occurrence or delay onset of malaria in human beings.
The vaccine was able to generate high immune response in human body through the use of CD8 T cells. Affirmative results have been observed in several studies in mice. These CD8(+) T cells (killer cells) are known to contribute to resistance against intracellular infections with certain viral, protozoan, and bacterial pathogens. They develop a wide range of effector mechanisms against deadly infections.
During the Phase IIa of the clinical trial 36 persons were subjected to two separate virus-based vaccine with the common malaria antigen at eight weeks gap. Out of those 14, the infection from the bite of malaria-infected mosquitoes was prevented in 3 people and the onset of infection was delayed in other 5. The researchers concluded that the immunity generated by the induced vaccine virus was able to successfully combat 90 per cent of the malaria parasites in infected bodies while the requirement is atleast 75 per cent.
Apart from having given the above figure of death tolls by malaria the world over, WHO also mentions that there has been a 26% reduction in this number over the last decade owing to the organisation’s recommended malaria control mechanisms. WHO lists 27 vaccine candidates which are undergoing clinical trials but are in early stages. Yet, there is an unfilled spot for an effective vaccine against this liver affecting parasitic disease. Even the most advanced candidate RTS,S/AS01 can only claim this spot after 2015 since by then more data will be available post the final trial of the drug vaccine. More would depend on the review by the European Medicines Agency which would most likely influence WHO’s recommendations for drug usage and distribution.
Any drug before coming to market and into circulation undergoes trials in phases, known as clinical trials, during which it is ensured that the drug provides effective and efficient medical treatment against the targeted disease with no long term side-effects to human body. It is a costly and long process consuming around 12-18 years.