The World Health Organization (WHO) approved on Wednesday (6) the first vaccine to help prevent malaria. The approval is the first step in starting a process of wide distribution of the immunization agent in the poorest countries. Malaria is a tropical disease that kills 500,000 people annually, half of them children in Africa under the age of five.
According to WHO Director-General Tedros Adhanom Ghebreyesus, himself a malaria researcher early in his career, “This is a historic moment. The long-awaited malaria vaccine for children is a breakthrough for science, child health and disease control.” In a statement on the UN’s international agency website, the biologist says prevention could “save tens of thousands of young people’s lives each year.”
It was based on the advice of an advisory body for immunization and another for malaria that the WHO decided to recommend the widespread use of the immunizer RTS, S or Mosquirix, by child populations in sub-Saharan Africa and other regions with moderate to high transmission of malaria by the parasite Plasmodium falciparum. The decision was based on a pilot program carried out in Ghana, Kenya and Malawi, which has served more than 800,000 children since 2019.
Why did the malaria vaccine take so long to be authorized?
In 2015, the results of a clinical trial in African children showed that the malaria vaccine from GlaxoSmithKline, a British pharmaceutical company, was able to prevent about 32 percent of severe cases of malaria in young children over a four-year period.
The low efficacy of the vaccine (compared to 90% of measles and chickenpox immunizers), the need to apply four doses in a year and a half, and the structural difficulties in administering it in precarious health systems have caused the WHO avoided recommending a generalized release of the immunizing agent.
However, to gather additional data on the safety of Glaxo’s vaccine, its effectiveness in real-life situations, and the feasibility of integrating it into routine childhood immunization programs, WHO experts mandated that trials be implemented in three African countries: Kenya, Malawi and Ghana.
Source: GHTC/Wikimedia Commons/ReproductionFonte: GHTC/Wikimedia Commons
Malaria Vaccine Pilot Test Results and Future Perspectives
After carrying out vaccination programs in the three countries, in child health clinics, the main findings were as follows:
- Feasibility: the vaccine proved to be viable, improves health and saves lives, with good coverage, even when applied during the covid-19 pandemic;
- Reach: The data showed that the RTS,S increased equity in access to malaria prevention, reaching those previously unreached;
- Safety: after the application of 2.3 million doses, the vaccine showed a favorable safety profile;
- Negative impacts: in areas covered by vaccination, there was no reduction in the use of insecticide-treated nets, in the adoption of other types of childhood vaccines or in the search for medical assistance for febrile illnesses;
- Real result: 30% reduction in cases of severe and deadly malaria, even in areas with insecticide-treated bed nets and good access to diagnoses and treatments;
- Cost-effectiveness: The relationship between costs and the outcome of vaccination programs proved to be good, mainly due to Glaxo’s decision to sell Mosquirix at no more than 5% above its cost price.
The main reason the malaria vaccine took so long to produce was lack of investment. Fighting a tropical disease does not have the same appeal as those most common in rich countries. Another important limitation is the genetic complexity of the P. falciparum which has about 5,000 genes, a multitude when compared to the covid-19 virus, SARS-CoV-2, which has only 13.