In just a few days, we’ll be celebrating World Malaria Day – and this year marks a particularly special occasion because it’s the first since the World Health Organization (WHO) recommended widespread use of the RTS,S/AS01 (RTS,S) malaria vaccine among children in sub-Saharan Africa and other regions with moderate to high Plasmodium falciparum malaria transmission.
As such, I’m delighted to bring you a special edition of the Curator, featuring an interview with Mgaywa GMD Magafu, Technical Officer and Regional Focal Person of the Malaria Vaccine Implementation Programme (MVIP) at WHO. Scroll on to read – and enjoy!
Backing the bivalent. Emergent COVID-19 variants pose a continued threat to global health; however, a recent phase 2/3 study of a bivalent vaccine has shown promising antibody responses to ancestral SARS-CoV-2 and the beta variant. The results suggest that bivalent booster vaccines may be an effective future defense when responding to emerging variants.
Brainy biomarkers. Though antimicrobial susceptibility tests (ASTs) are valuable in the fight against drug-resistant pathogens, the associated labor and financial costs limit their wider use. After developing a novel automated system of Clinical Antimicrobials Susceptibility Test Ramanometry (CAST-R), researchers were able to gain a 10-fold increase in speed to results compared with standard ASTs. This, alongside automation, general application, and reliability of the CAST-R system highlights its potential for broader use.
Time after time. In a new study into how the immune system protects against malaria, researchers have found that primary infection is associated with increased inflammatory cytokines and γδ T cell expansion, while previous infection leads to more parasite-specific antibodies and CD16+ monocytes, which coincided with reduced parasitemia and hospitalization duration. Overall, their findings point towards the mechanisms behind tolerance development after repeated malaria exposure.
Mozzie movements. Researchers have developed a new metapopulation framework that enables them to identify the most effective areas to release Wolbachia-infected mosquitoes, with the aim of decreasing global dengue prevalence. The framework factors in competition dynamics between Wolbachia-infected and wild-type mosquitoes, cross-contagion between humans and vectors, dynamics of human movement throughout the day (such as daily commutes), and the distribution of the human population.
In Conversation...
With Mgaywa GMD Magafu, Technical Officer and Regional Focal Person of the Malaria Vaccine Implementation Programme (MVIP), WHO, Brazzaville, Republic of the Congo.
It’s been almost six months since the WHO recommended the first malaria vaccine. What progress has been made in developing vaccine implementation strategies in sub-Saharan Africa?
Next steps for the first malaria vaccine are well underway. International financing has been secured to support expanded introduction of the vaccine. Initial funding (US$155.7 million for 2022–2025) has been secured from Gavi, the Vaccine Alliance to support the introduction, procurement, and delivery of the malaria vaccine for Gavi-eligible countries in sub-Saharan Africa.
WHO guidance is also now available to countries while they consider whether and how to adopt the vaccine as an additional tool to reduce child illness and deaths from malaria. WHO has published an updated position paper on the malaria vaccine, and WHO’s recommendation for the vaccine was recently added to the WHO guidelines for malaria.
Countries are now considering whether to adopt the vaccine as part of a comprehensive malaria control plan, with vaccine scale-up to additional countries expected to begin in late 2023.
Can you tell us what has been learned so far from the pilot – and expectations for the pilot through to 2023?
The Malaria Vaccine Implementation Programme (MVIP) pilot is a public health program that includes a country-led, phased introduction of the RTS,S malaria vaccine to at-risk children in areas of moderate to high malaria transmission by the Ministries of Health of Ghana, Kenya and Malawi. It also includes an evaluation of the vaccine in real-life routine immunization settings. WHO provides overall coordination and technical leadership for the programme.
Since 2019, over 900,000 children have been reached with at least one dose of the vaccine through pilot introductions in Ghana, Kenya, and Malawi. Three years later, the pilots continue to benefit at-risk children and generate insights and lessons learned for broader deployment.
Pilot findings during the first two years of routine immunization affirm that the malaria vaccine is safe, feasible to deliver, and reduces deadly severe malaria. After the vaccine was introduced, there was a substantial reduction in children being hospitalized and in child deaths in the age group that is eligible to receive the vaccine.
The vaccine increases access to malaria prevention – it reaches about 80–90 percent of children through the established immunization platform and, because of this high uptake, is reaching children who are not using other forms of prevention, such as insecticide-treated nets. Furthermore, the introduction of the malaria vaccine did not result in a decline in the use of other malaria interventions.
The pilots will continue throughout 2023 to understand the added value of the fourth vaccine dose and to measure the impact of vaccine introduction on lives saved.
What challenges do you anticipate that the WHO will face in getting the vaccine to children in sub-Saharan Africa?
Projected RTS,S/AS01 vaccine production capacity stands at a maximum of 15 million doses per year in the short to medium term, while demand is estimated to exceed 80 million doses annually. Anticipated high demand for the vaccine will far outstrip supply in the next few years – the supply gap could be prolonged without swift intervention and new investments to increase supply, so Africa can reap the benefits of this new malaria prevention tool.
WHO and its partners are working to accelerate supply by increasing manufacturing capacity of RTS,S and facilitating the development of other first-generation and next-generation malaria vaccines. WHO is coordinating the development of a framework for allocation of the limited vaccine supply to guide where the initial doses of vaccine will be deployed, with an aim to prioritize supply for areas of greatest need and highest malaria burden until supply meets demand.
The WHO recommendation of a malaria vaccine and the availability of Gavi financing for large-scale deployment signals to manufacturers that the world needs and wants malaria vaccines – and is willing to invest in them.
If we can deliver it to the children who need it, this long-awaited malaria vaccine will benefit Africa, which shoulders the heaviest burden of the disease. Working together, we must seize this opportunity to help get malaria progress back on track and improve child health.
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