In the fight against malaria, various malaria control programs have been developed and implemented. However, lives are still being lost because of the inability of most developing countries in Africa to access insecticide treated bed nets or other malaria prevention measures.

The World Health Organization launched a pilot program that aimed to immunize around 360,000 children each year in three African countries which are Ghana, Kenya and Malawi with the first and only vaccine known to reduce malaria in children.

The vaccine, called RTS,S/AS01 (Mosquirix) developed by GlaxoSmithKline (GSK) was deployed in 2019 and projected to April 2021. Extensive testing in clinical trials in the sub-Saharan region of Africa have confirmed that the malaria vaccine reduces malaria significantly including life-threatening severe malaria in young children.

From a recent World malaria report, it was found that over the last four years progress in reducing malaria has hit a plateau. In 2019, there were an estimated 229 million malaria episodes and 400,000 deaths from the disease. Over 90% of malaria deaths which occur in Africa, the majority – more than 265,0000 – involve young children.

However, this vaccination program is not without controversy. The RTS,S vaccine only prevents in 4 in 10 malaria cases, and must be given as 4 injections over 18 months. Some malaria researchers question the wisdom of spending time and money on the pilot programme, given that a handful of more effective vaccines are in clinical trials and could be available by the time RTS,S is ready for regular use. They say that the decades-long effort to roll out RTS,S exemplifies the plodding progress on vaccines for disease that affect the world’s poor, and highlights the need for a more efficient path forwards.

Currently the malaria vaccine is being introduced in areas where children are at high risk of illness and death from malaria. In these areas as much as 60% of childhood outpatient health facility visits are due to malaria. The RTS,S vaccine can reduce cases of malaria and severe malaria, hospital admissions and blood transfusions – it is expected to decrease child deaths and relieve health systems.

The introduction of Mosquirix in the routine health systems of Ghana, Kenya and Malawi by the respective country health ministries and World Health Organization (WHO) is in line with further development of the vaccine. The question of mosquito control and reduction in transmission cannot be wished away on the use of a vaccine. In the Phase 3 clinical trials, the efficacy was upon the use of other malaria control interventions, so the vaccine is implemented as an additional tool in the fight against malaria.

Other malaria vaccine candidates are in development or trail phases, including transmission-blocking vaccines that target the sexual stage of parasite development in the mosquito. The world leading global health organizations have developed the Malaria Vaccine Technology Roadmap for accelerating development of a highly effective malaria vaccine.

The roadmap involves the following strategic goals for malaria vaccines by 2030:

• Develop and license malaria vaccines with protective efficacy of at least 75% against clinical malaria for areas with ongoing malaria transmission.
• Develop malaria vaccines that reduce transmission and human malaria infection, enabling elimination in multiple settings through mass vaccination campaigns.

REFERENCES

1. https://www.who.int/news/item/20-04-2021-rts-s-malaria-vaccine-reaches-more-than-650-000-children-in-ghana-kenya-and-malawi-through-groundbreaking-pilot-programme#:~:text=Over%2090%25%20of%20malaria%20deaths,the%20need%20for%20blood%20transfusions.
2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6697768/
3. https://www.afro.who.int/news/malaria-vaccine-pilot-africa-one-year-new-vaccine-could-boost-kenyas-malaria-fight
4. https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1003377
5. https://www.cdc.gov/malaria/malaria_worldwide/reduction/vaccine.html
6. https://www.nature.com/articles/d41586-019-01342-z
7. https://www.healio.com/news/infectious-disease/20190423/who-launches-malaria-vaccine-program-in-3-african-countries