malaria prevention

Hope for reducing Malaria?

In 2010 an estimated 219 million cases of malaria occurred worldwide and 660,000 people died, most (91%) in the African Region (CDC, 2013). This global pandemic has been a huge public health issues , particularly in Africa. Although numerous interventions have been used to reduces the deaths from malaria, long term, more cost effective solutions still elude researchers.

Developing an effective vaccine has been a major goal in global health for years. However, malarias unique and cyclic pathology has challenged researchers in developing an effective vaccine to prevent infections. To date numerous vaccines have been developed and tested but none have been licensed.

The RTS,S malaria vaccine candidate was created in 1987 by researchers at GlaxoSmithKline laboratories. Early clinical development was done in collaborations with the Walter Reed Army Institute for Research. In 2001, GlaxoSmithKline and the PATH Malaria Vaccine Initiative, with grant monies from the Bill & Melinda Gates Foundation, entered into a public-private partnership to develop an RTS,S-based vaccine for infants and young children living in malaria-endemic regions in sub-Saharan Africa (Malaria Vaccine Initiative PATH, 2013).

The RTS,S vaccine boosts the immune response to attack the p.falciparum  malaria parasite when it firsts enters the host bloodstream. It is designed to prevent the parasite from infecting, maturing, and multiplying in the liver (Malaria Vaccine Initiative PATH, 2013).

The vaccine has already been through the first two phases of clinical trials and is currently undergoing phase three trials.  Because the vaccine has a clinically accepted safety profile, it is now being administered in a blind study to test for phase III efficacy.  This phase started in May 2009 and delivers vaccine to children and young in seven sub-saharan African countries. Countries included in the study include Burkina Faso, Gabon, Kenya, Malawi, Mozambique, and Tanzania. In total 15,460 participants were recruited for the study. Each participant received three initial doses and  some were selected to receive a fourth to test the efficacy of a booster. Those in the study that received placebo did not leave empty handed. As an incentive to participate in the study, free healthcare was provided to participants.

Initial results  of the Phase III trials have been promising. After a year of follow-up  New England Journal of Medicine reported  that three doses of RTS,S reduced clinical malaria by 56% in children 5-17 months of age at first vaccination. In infants 6-12 weeks of age at first vaccination with RTS,S, clinical malaria was reduced by 31%. Results after a three year follow up showed that infants between 6-12 weeks of age, efficacy against clinical malaria were 27% and 444 cases of clinical malaria were prevented per 1,000 vaccinees (Malaria Vaccine Initiative PATH, 2013).

Final results of the trial are anticipated for 2014 and some hope to publically distribute the vaccine by 2015. In January 2010, GSK announced that the RTS,S pricing model will cover the cost of manufacturing the vaccine together with a small return of around 5 percent, which will be reinvested in research and development for second-generation malaria vaccines or vaccines against other neglected tropical diseases (Malaria Vaccine Initiative PATH, 2013).

Although this represents a great scienctific breakthrough and has major implication for African and global health, Malaria prevention is far from being achieved. Funding the price and delivery of this vaccine to the masses will pose several unique public health challenges. Countries will have to consider the logistics of delivery in their vaccine programs and most likely extend them. Setting schedules for vaccine administration may also be a large source of debate. Nonetheless, the RTS,S vaccine appears to be promising and may be a case study for future international health students.

Bibliography

CDC. (2013). CDC's Malaria Program. CDC Center for Global Health.

Malaria Vaccine Initiative PATH. (2013). Fact Sheet: The RTS,S malaria vaccine cadidate. GSK, MVI PATH.