Next-Gen malaria jabs can achieve WHO strategic goal

Almost half of the world’s population is at risk of malaria infection with some 249 million people diagnosed with the disease in 2022. Then, it claimed 608,000 lives, mostly in sub-Saharan Africa, where children under five accounted for staggering 80 percent of the deaths.

The World Health Organization (WHO) Global Technical Strategy for Malaria targets a 90 percent reduction in mortality and incidence rates by 2030. three-quartersKey interventions include maintaining the efficacy of artemisinin-based therapies, developing new non-artemisinin combinations and vector control tools and addressing emerging drug/insecticide resistance and intervention gaps like outdoor biting. Others are enhancing diagnostics for asymptomatic infections and point-of-care G6PD tests.

While progress in reducing malaria cases and deaths has stagnated since 2015, there is optimism, fuelled by the growing number of pipeline candidates and emergence of innovative and promising products and technologies.

As of last December, at least 151 malaria counter-measures were in development globally with vaccines constituting almost half (43 percent) of the active pipeline, taking over from drugs (27 percent), which held a substantial share of over one-third of the pipeline (36 percent) in 2015. The remaining pipeline is composed of diagnostics (19 percent), biologics (five percent) and vector control products (six percent).

The emergence of malaria vaccines like RTSS and R21/Matrix-M shows a great potential in reducing the disease burden. Since its rollout in 2019, RTSS, has reduced malaria-associated deaths by 13 percent. A 2023 WHO-recommended R21/Matrix-M reduced malaria cases by 75 percent in a clinical trial, underscoring the substantial impact future vaccines could have.

A malaria vaccine pipeline is not just growing; it’s thriving. The number of candidates in clinical development has doubled since 2015. What’s better, these candidates aren’t just entering clinical development but progressing.

For instance, since 2019, the number of candidates in phase II have nearly doubled, three quarters of which target P. falciparum, with less than a fifth targeting P. vivax.

On the life cycle, up to 39 percent of the candidates target the pre-erythrocytic stage and 38 percent target blood stages. And as with the RTS,S and R21/Matrix-M, over half of the pipeline is based on a sub-unit approach, involving using a specific part of the parasite to stimulate an immune response.

Impressive strides. However, vaccines with current or similar efficacy profiles are only helpful when used as part of a comprehensive malaria control strategy, which must include vector control measures. An ideal malaria vaccine would reduce infection and clinical malaria by 90 percent and block community transmission. Thus, it must target multiple stages of the parasite’s lifecycle with the potential to impact transmission.

We must now focus on developing the second generation of malaria vaccines that can fulfil these WHO strategic goals. This is the surest path to “Accelerating the fight against malaria for a more equitable world”, as per this year’s World Malaria Day theme.