WHO’s 2023 World malaria report, shared in November 2023, suggests that, despite efforts to increase access to interventions, more people are getting sick with malaria. A WHO statement that summarises the report describes it as an investigation of the “nexus between climate change and malaria”, suggesting that this is one of the greatest challenges that must be overcome by the global malaria response. However, it is not the only obstacle; WHO Director General, Dr Tedros Adhanom Ghebreyesus, comments in his foreword that “millions of people continue to miss out on the services they need” due to “conflict and humanitarian crises, resource constraints, and biological challenges”.
“These threats are undermining gains in the global fight against malaria.”
Dr Tedros reflects that the “global tally” of malaria cases in 2022 reached 249 million, which is “well above” the estimated number of cases before the COVID-19 pandemic. Although the report addresses key concerns about slow progress, it does recognise that progress is being made. For example, the first malaria vaccine recommended by WHO, RTS,S/AS01, has so far reduced early childhood deaths by 13% in Ghana, Kenya, and Malawi. The second safe and effective vaccine, R21/Matrix-M, was recommended by WHO in October 2023.
“A two-vaccine market will make broad scale-up across Africa possible.”
Dr Tedros states that there is much more to do, particularly in the face of the “added threat” of climate change, demanding “sustainable and resilient malaria responses”.
“A substantial pivot with much greater resourcing, data-driven strategies, and new tools is needed to rebuild momentum in the fight against malaria.”
Malaria trends from 2022
The report presents data from the past year, including the following:
- There were an estimated 249 malaria cases in 85 malaria endemic countries and areas.
- This is an increase of 5 million cases compared to 2021.
- The countries that contributed most to the increase were Pakistan, Ethiopia, Nigeria, Uganda, and Papua New Guinea.
- Malaria case incidence was about 58 per 1,000 population at risk in 2022.
- The proportion of cases due to P. vivax (Plasmodium vivax) decreased from about 8% in 2000 to 3% in 2022.
- 29 countries accounted for 95% of malaria cases globally.
- 4 countries (Nigeria, the Democratic Republic of the Congo, Uganda, and Mozambique) accounted for almost half of all cases globally.
- Estimated deaths declined in 2022 to 608,000, from an estimated 631,000 in 2020.
- The mortality rate decreased from 15.2 in 2020 to 14.3 in 2022.
- About 96% of malaria deaths globally were in 29 countries.
- 4 countries (Nigeria, the Democratic Republic of the Congo, Niger, and the United Republic of Tanzania) accounted for just over half of all malaria deaths.
Vaccine focus
The report reflects on the contributions of vaccines to malaria elimination efforts, most notably the introduction of RTS,S/AS01. This began in 2019 in Ghana, Kenya, and Malawi through the Malaria Vaccine Implementation Programme.
“To date, the RTS,S vaccine has been administered to over 2 million children…and has been shown to be safe and effective, resulting in a drop of 13% in all-cause early childhood deaths and a substantial reduction in severe malaria.”
This success reflects “high” vaccine uptake and is complemented by “no reduction” in insecticide-treated bed nets (ITNs). Following the WHO recommendation for use of this vaccine in October 2021, “at least 28 countries” in the WHO African Region have expressed an interest in introducing the vaccine. However, initial “constrained” supply demanded a framework for allocation was developed and applied to prioritise the 18 million doses available for 2023-2025 to 12 countries. The first doses of this vaccine have started arriving in countries towards the end of 2023 and the expectation is that they will be rolled out in childhood immunisation programmes by early 2024.
In October 2023 the R21/Matrix-M malaria vaccine became the second vaccine to be recommended by WHO for the prevention of malaria in children who live in areas of risk. This addition to the ongoing rollout of the first approved vaccine is expected to boost vaccine supply, saving “tens of thousands of young lives”.
However, the news isn’t all positive, with the report identifying a fall in “overall funding for vaccines” for the fifth consecutive year. Funding reached a “record low” of US$ 106 million in 2022. Responsible for “over 30% of this fall” is The Bill and Melinda Gates Foundation. Furthermore, industry and the European Commission have contributed to the fall. WHO emphasises that eradication relies on “mitigating biological threats and developing more efficacious tools”, which include “highly efficacious vaccines”.
The threat of climate change
“Climate change is recognised as one of the biggest threats and challenges to human health and well-being – and vulnerable groups are hit particularly hard.”
The effect of a changing climate on malaria transmission is “likely to vary across social and ecological systems”, but the report is clear that the most vulnerable will be the first to feel it. WHO offers a few examples of how climate change influences malaria transmission and burden. One is that the malaria parasite and mosquito vectors are sensitive to “temperature, rainfall, and humidity”.
The “ideal mosquito breeding and survival” temperature is between 20°C-27°C. Thus, a slight temperature increase in cooler zones could encourage new malaria cases, as has been reported “over several decades in some African highlands”. There are also indirect effects; for example, disrupted supply chains or population displacement will threaten access to “critical malaria commodities”.
Although data on the longer-term effects of climate change on malaria transmission are “sparse”, some of the “Strongest available data” from recent decades have found that climate change has contributed to malaria transmission in areas that were previously malaria free. Through a short-term lens WHO reflects that extreme weather in Pakistan led to the melting of glaciers and surging of rivers in the north and “excessive rainfall and flooding” in the south. Subsequent standing water created the “ideal breeding ground” for mosquitoes; malaria cases increased “fivefold” in comparison with the year before. At the same time the floods compromised infrastructure and isolated people.
What can be done?
In WHO’s press release, Dr Matshidiso Moeti, WHO Regional Director for Africa, comments on the importance of recognising the “multitude of threats that impede our response efforts”.
“Climate variability poses a substantial risk, but we must also contend with challenges such as limited healthcare access, ongoing conflicts and emergencies, the lingering effects of COVID-19 on service delivery, inadequate funding, and uneven implementation of our core malaria interventions.”
Dr Moeti demands a “concerted effort” to tackle the “diverse threats”. This should foster “innovation, resource mobilisation, and collaborative strategies”.
If you’ve read the report do let us know your response to it. What’s next on the vaccine front, and how can we increase funding for this critical intervention? We look forward to an update on progress towards malaria eradication at the Washington Congress in 2024. Do get your tickets for this today! If you can’t join us, why not subscribe for more?
