A malaria vaccine?

GlaxoSmithKline's vaccine trials could help combat the dreaded disease

The promising results from trials of a malaria vaccine developed by GlaxoSmithKline have kindled hopes of a breakthrough in combating this mosquito-transmitted disease that infects nearly 250 million people, killing about a million every year. The findings of the human tests of the experimental vaccine (named RTS,S), conducted in Kenya and Tanzania and published in the New England Journal of Medicine, show a success rate of between 53 and 65 per cent in protecting infants against malaria. This level of success is viewed with satisfaction as it is the best ever in the case of this vector-borne malady. This development is significant also because it is the first-ever vaccine against any parasitic disease that has qualified for the third and final round of efficacy trials. Equally noteworthy is the confirmation that it can be safely co-administered to children along with the standard immunisation shots against diphtheria, tetanus, whooping cough and others. If it gets through the next phase of clinical tests, the first generation malaria vaccine may be a reality in the near future — any time after 2011.

 

Unlike small pox and polio, which have either been stamped out or controlled through vaccination, malaria has been defying all attempts to contain it. The menace has proved particularly difficult to surmount because people remain exposed to mosquito bites through their lives and the parasites, on getting into the blood, live and reproduce inside the body to cause malarial fever and, at times, brain infection. Unfortunately, the remarkable successes achieved in taming malaria in the 1950s and 1960s with the use of the now banned insecticide DDT began fading away from the 1970s after the development of pesticide-resistance among mosquitoes and the emergence of new, hardier mosquito strains. Besides, no alternative to DDT, in terms of cost-effectiveness and efficacy, has been found so far. This has made vaccine development imperative. From this standpoint, Glaxo deserves kudos for investing nearly $300 million (by the company's reckoning) on this pursuit over 25 years. Glaxo's effort has been supported by the Malaria Vaccine Initiative, and by the Bill and Melinda Gates Foundation, besides scientists from across the continents; future work on the vaccine-based malaria control programme will have to be funded by other donors and governments. For, a single vaccine might not work against all the strains of pathogen because the antigen that a vaccine would have to target might vary, depending on the stage of the parasite's life cycle.

Pending the availability of an effective vaccine, the World Health Organisation has begun advocating the use of insecticide-treated bed-nets in the malaria-endemic regions of Asia and Africa. This is a costly solution, considering that the scourge is most prevalent in poor countries and in thickly populated areas. It would be better if investment were made in developing a series of vaccines against malaria, and according the task the same priority as Aids and cancer.