The World Health Organization (WHO) has taken a remarkable leap to curb the spread of the parasitic disease, malaria, by endorsing the world’s first Malaria Vaccine. This endorsement is anticipated to encourage efforts to manage the deadly disease which is caused by parasites transmitted through the bite of infected female Anopheles mosquitoes. Although preventable and curable, malaria continues to be a significant global health threat.
About the Malaria Vaccine: RTS,S/AS01
Trade-named Mosquirix, the RTS,S/AS01 vaccine targets Plasmodium falciparum, the most prevalent malaria strain in Africa. Developed by British drugmaker GlaxoSmithKline in 1987, it is the only vaccine that has shown partial protection in young children. The active substance in Mosquirix consists of proteins found on the surface of the Plasmodium falciparum parasites (PFP). The vaccine stimulates the immune system to defend against the initial stages of malaria when the PFP enters the bloodstream via a mosquito bite and infects liver cells. Additionally, it provides protection against Hepatitis B virus infection in the liver.
Potency of the Vaccine
The vaccine provides about 30% prevention against severe cases of malaria in children, making it the only approved vaccine for the disease. It received approval from the European Union’s drugs regulator in 2015 based on its benefits outweighing the risks. Side effects are rare, though some may experience fever resulting in temporary convulsions.
Challenges Associated with the Vaccine
Despite the breakthrough, the vaccine comes with several challenges. A child must receive four injections before turning two years-old, sometimes at intervals incompatible with traditional vaccine schedules. Testing showed that even after receiving four doses, the vaccine prevented only approximately 40% of detectable malaria infections. Also, the duration of the protection provided by the vaccine remains unclear. Experts fear that vaccination might lead to negligence in using mosquito nets and seeking prompt medical care for fevers in children. There is concern about malaria parasites developing resistance to the vaccine, just as they have to other drugs.
Global Burden of Malaria
In 2019, there were an estimated 229 million cases of malaria worldwide with around 4,09,000 deaths. The most affected group was children under five years, who accounted for 67% of all malaria deaths that year. India reported around 5.6 million cases in 2019, which increased significantly to approximately 20 million cases in 2020.
Countries that Eliminated Malaria
Over the last two decades, the WHO Director-General has certified 11 countries as malaria-free including United Arab Emirates (2007), Morocco (2010), Turkmenistan (2010), Armenia (2011), Sri Lanka (2016), Kyrgyzstan (2016), Paraguay (2018), Uzbekistan (2018), Algeria (2019), Argentina (2019), and El Salvador (2021).
Way Forward
The next steps for the WHO-recommended malaria vaccine include securing funding for broader rollout in endemic countries and decision-making at the country level on the inclusion of the vaccine in national malaria control strategies.