All You Need to Know about the Malaria Vaccine


In 2020, the estimated number of malaria deaths stood at 627,000. Over 75% of these deaths were in children and malaria remains one of the leading causes of death in sub-Saharan Africa. In October this year, the WHO approved the first malaria vaccine for widespread use across regions in which malaria is endemic [1].


Why do we need a vaccine?


As demonstrated during the Covid-19 pandemic over the last 2 years, the impact of an effective vaccine on the lives and futures of those affected can be profound. This is potentially of even greater effect in malaria due to the population that it typically affects, being younger and often previously healthy. The introduction of a vaccine is yet another tool in the armoury of malarial prevention. Combating such a disease may have not only the short term health benefits for the individual but substantial economic and social impacts in the longer term. .

Aside from the economic and societal benefits, recent data shows the emergence of notable resistance to artemesinin antimicrobials of up to 10% in certain African countries. This clearly will significantly impact the effect of current treatment regimens and therefore the development of other treatment and prevention methods is vital.

WHO guidelines recommend rectally administered artemether for severe malaria in a community setting prior to urgent referral to secondary care. The original data recommending this was derived from trial settings with relatively well controlled treatment pathways, however translating this into the real world has seen some concern about reductions in onward referrals for diagnosis and failure of treatment completion, leading to increased mortality and morbidity [2,3,4].


What do we know about the vaccine?


“As part of the Malaria Vaccine Implementation Programme, in January 2016, WHO recommended the RTS,S malaria vaccine for pilot introduction in selected areas of three African countries: Ghana, Kenya and Malawi

Data from the pilot introductions have shown that the vaccine has a favourable safety profile; significantly reduces severe, life-threatening malaria; and can be delivered effectively in real-life childhood vaccination settings, even during a pandemic.

On 6 October 2021, WHO recommended that the RTS,S malaria vaccine be used for the prevention of P. falciparum malaria in children living in regions with moderate to high transmission.” [1]


What is the anticipated vaccine rollout effect?


As with any vaccine, the greatest impact, and greatest cost-effectiveness, will be seen in areas in which the disease is most prevalent. Interestingly, long-lasting insecticide treated nets (LITNs) remain of greatest cost-effectiveness when modelled against other interventions, but once their impact and availability has been maximised, anti-malarial vaccines can still play a significant role in reducing disease burden and mortality [5].  

In the pilot studies, over two thirds of the children who were not using bed-nets in the trial were reached by the vaccine, which suggests both a need for further expansion of the LITNs, but also show that the vaccine is a useful method to reach those currently without such preventative options.

In areas with disease prevalence of 10-65%, it is estimated that per 100,000 children vaccinated, almost 94,000 cases would be averted with a reduction of nearly 400 deaths for the three dose vaccine schedule. These numbers rise to over 115,000 cases avoided and 500 deaths when a four dose vaccine schedule is used [6].


Where will it be rolled out?


Gavi, the global vaccine alliance, have provided an initial investment of over $155 million for the vaccine to be rolled out to Gavi-eligible countries in sub-Saharan Africa between 2022-2025 [7].


The vaccine has the potential to save many lives and to provide significant economic and social benefits in the areas in which it is introduced. However, it will not be a silver bullet to eradicate malaria. We must stay vigilant in promoting current malaria protection measures and ensuring best practice in malaria treatment. 

At MedShr we are building a network of health care professionals interested in malaria and its global impact. We aim to promote awareness and deliver education around the disease.

Join our Malaria Global Education Network - through sharing your experiences of managing patients with suspected malaria and your practical solutions to overcome barriers to prophylaxis, screening and treatment, we believe this network will help to improve the lives of patients globally and ultimately save lives.



References


[1] World malaria report 2021

[2] Rectal administration of artemisinin derivatives for the treatment of malaria 

[3] The preclinical discovery and development of rectal artesunate for the treatment of malaria in young children: a review of the evidence: Expert Opinion on Drug Discovery: Vol 16, No 1

[4] Rectal artesunate for pre-referral treatment of severe malaria - WHO Guideline

[5] Modelling the cost-effectiveness of introducing the RTS,S malaria vaccine relative to scaling up other malaria interventions in sub-Saharan Africa | BMJ Global Health

[6] Public health impact and cost-effectiveness of the RTS,S/AS01 malaria vaccine: a systematic comparison of predictions from four mathematical models - The Lancet

[7] Gavi Board approves funding to support malaria vaccine roll-out in sub-Saharan Africa


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