Is There A Vaccine Available For Malaria?
The one and only approved vaccine for prevention of malaria is RTS,S which completed its trials in midst of 2015. But it has much lesser efficiency of 26 to 50% and this formed a basis on which WHO or World Health Organization decided to ban the prevention of malaria by this vaccine in new-borns and children between the ages of 6 to 12 years of age. There are several trials going on to generate a cost-efficient and promising vaccine against malaria parasite, the Plasmodium. But they are all under clinical trials and it will not be called a long shot theory if one says malaria vaccine is a phenomenon of later decade. Since past time we have developed vaccine for worse diseases and it is more of a reason that development of an apt vaccine against malaria became a tortoise trail. But, good news is researchers are now showing their interest in Plasmodium and we are so close to develop malaria vaccine like never before.
Future of Control and Prevention of Malaria
The Global Technical Strategy for Malaria is the future of malaria and human health. According to this strategy some goals were adopted in May 2015, which would be implied in the year of 2016 and they are targeted to be achieved by the year 2030. These goals include-
- Global reduction in malaria mortality rate with comparison to year 2015.
- Global reduction in incidence of malaria with comparison to year 2015.
- Elimination of the disease from the countries to which malaria was transmitted during year 2015.
- Prevention of recurrence of malaria globally and especially in the countries that are free from malaria.
The goal of prevention of the disease also includes development of vaccine against malaria and imparting its influence as extensive clinical trials of vaccine by different manufacturers in Asia, Africa and the United States of America.
What are the Current Clinical Trials Running For Malaria Vaccine?
The modern research is more focused in developing vaccine consisting of attenuated whole organism and recombinant protein type.
SPf66: It is an artificially developed, peptide based vaccine invented by the team of Manuel Elkin Patarroyo from Colombia.
CSP: Another vaccine called as the CSP (Circum-Sporozoite Protein) was developed much earlier at that time and also produced desired results, but additionally it carries a recombinant (Asn-Ala-Pro15Asn-Val-Asp-Pro)-2 Leu Arg also called as R32LR.
NYVAC-Pf7: This vaccine was developed with a whole new idea of a multi – stage vaccine. It consists of antigenic genes of seven of Plasmodium falciparum genes. All of these samples were taken at different stage of maturation cycle of the insect. PfSSP2 also called as sporozoites surface protein and CSP both were taken from sporozoite stage. One antigen from liver stage and three from the erythrocytic stage were also included. The thing that made this research so popular was its trial in the Rhesus monkey for the first time and to much more surprise it produced excellent results too. But human trials were not even close to the animal ones. Over 90% of the test subjects developed very poor immune responses. Interestingly, some candidates shown complete resistance towards P. falciparum and this was a breakthrough that acted as inspiration for the researches carried out later on.
NANP: During 1995, 19-5.1 field trials of NANP were found to be hugely promising. It was the best vaccine to be entered human trials that millennium as among 194 test subjects (who were children) only eight candidates failed to achieve higher antibody level and to more a surprise not a single one suffered from any symptomatic malaria during a 12-week follow up. The vaccine carried nineteen repeats of surface protein of sporozoites stage and 5.1 type of export protein of schizonts stage. The limitations were the concentration of mere 20% peptides and lower levels of immunogenicity.
But finally we can say that vaccine for malaria is not a journey to a far galaxy anymore. It is within reach of the research facilities and will be seen in the general pharmacies within this decade.
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