The World Health Organisation on Wednesday approved the first vaccine against malaria which will be used on children in Africa and later be promoted for global use. Though the approval of this vaccine by the apex health organisation is a milestone, it is also important to note that the vaccine is only effective against one species of the Plasmodium parasite.
The RTS,S/AS01 vaccine produced by pharmaceutical giant GlaxoSmithKline was earlier approved by the European Medicines Agency for children in 2015. Over the six years research has emerged suggesting that the malaria vaccine acts on the falciparum species of the parasite. Transmitted by the female Anopheles mosquito, the species of the parasite can only be determined after thorough bloodwork and research.
Permitted to be used in sub-Saharan Africa currently, the approval of this vaccine is a move to reduce the burden of malaria in this region. Over 2,60,000 African children under the age of five die from malaria annually. According to the latest World malaria report, released on 30 November 2020, there were 229 million cases of malaria in 2019 compared to 228 million cases in 2018. The estimated number of malaria deaths stood at 4,09,000 in 2019, compared with 4,11,000 deaths in 2018.
The WHO African Region continues to carry a disproportionately high share of the global malaria burden. In 2019, the region was home to 94% of all malaria cases and deaths.
According to Dr Tedros Ghebreyesus, Director General of the WHO, "Using this vaccine on top of existing tools to prevent malaria could save tens of thousands of young lives each year."
In recent years, WHO and its partners have been reporting a stagnation in progress against the deadly disease. "For centuries, malaria has stalked sub-Saharan Africa, causing immense personal suffering," said Dr Matshidiso Moeti, WHO Regional Director for Africa. "We have long hoped for an effective malaria vaccine and now for the first time ever, we have such a vaccine recommended for widespread use. "
What Is The RTS,S Anti- Malaria Vaccine?
The results of the falciparum vaccine candidate, RTS,S were first published in 1997 post which it has been evaluated in a series of clinical trials culminating in Phase 3 testing. The European Medicines Agency approved its use in 2015.
The 2015 approval came through after placebo-controlled trials in over 15,000 children and infants, the vaccine reduced infection by 36% in children and by 28% in infants. While experts in the field applauded the launch of a vaccine against malaria but they were also concerned with its low efficacy. The WHO decided to launch a pilot before announcing the implementation of the vaccine in the national programs of African nations.
Based on findings from this ongoing pilot study in Ghana, Kenya and Malawi that has reached more than 800 000 children since 2019, WHO recommended a 4-dose regime in children from 5 months of age for the reduction of malaria disease and burden. As of October 6, over 2.3 million doses of this vaccine have been administered to children.
Malaria elimination and prevention programs focus on behavioural change interventions such as using mosquito repellents, using insecticide treated long lasting bed nets. From the pilot study, it emerged that the more than two-thirds of children in the 3 countries who are not sleeping under a bed net are benefitting from the RTS,S vaccine. Furthermore, areas where the vaccine has been introduced, there has been no decrease in the use of insecticide-treated nets, uptake of other childhood vaccinations or health seeking behavior for febrile illness.
The WHO believes that when used in combination with existing prevention measures, RTS,S will accelerate the pace of malaria progress in Africa, improve child health and save lives.
Vaccine Only For Plasmodium Falciparum
Malaria is caused by five different species of the plasmodium parasite- falciparum, vivax, ovale, malariae. knowlesi.
While the vaccine targets falciparum which is the predominant species in Africa, South East Asian regions as well as the regions of the Americas have a higher proportion of cases caused by the vivax species. Even in India, the highest number of cases detected are caused by the vivax.
The vaccine's effects on the other species is not yet known. Thus, the vaccine is most beneficial for the African region which has the highest malaria disease burden.