Context:

Georgia’s recent designation by the WHO as the 45th nation to eradicate malaria marks an important turning point. Malaria continues to kill more than 600,000 people every year and cause over 240 million cases despite decades of international efforts.

Issues Surrounding Malaria Vaccines

1.   Adaptability of the Malaria Parasite:
One of the primary issues is the malaria parasite’s remarkable ability to adapt and evolve. Plasmodium, the parasite that causes malaria, frequently changes its surface proteins (antigenic variation), making it difficult for the immune system to recognize and fight it.

2.   Limited Efficacy of Existing Vaccines:
The RTS, S vaccine, although a breakthrough, has limited efficacy. It reduces malaria cases by only about 36% after four doses over four years, far below the 90-95% effectiveness seen in vaccines for other diseases like measles.

3.   Multi-Stage Lifecycle:
Malaria's lifecycle involves multiple stages across two hosts—mosquitoes and humans—meaning any vaccine must address various stages of the parasite's development. For example, the RTS, S vaccine targets the liver stage, but it doesn’t address the blood stage, where symptoms manifest.

4.   Logistical Challenges in Distribution:
Malaria vaccines like RTS, S require multiple doses, which poses significant logistical challenges in resource-limited regions where healthcare infrastructure is often inadequate.

5.   Underfunding of Research:
Malaria vaccine research has faced chronic underfunding, especially due to geopolitical and economic reasons. Malaria primarily affects low-income regions in Africa and South Asia, leading to less investment in vaccine development. Additionally, the high costs of research and uncertain returns have discouraged pharmaceutical companies from investing heavily in malaria vaccines.

About Malaria:

Malaria is a serious and potentially life-threatening disease caused by Plasmodium parasites, transmitted to humans through the bites of infected female Anopheles mosquitoes. It primarily affects individuals in tropical regions and can result in severe illness and death if not treated effectively.

Malaria is most commonly found in tropical and subtropical regions of the world, particularly in sub-Saharan Africa, Southeast Asia, and parts of Latin America.

Symptoms:

The common symptoms of malaria include:

• Fever
• Chills
• Headache
• Fatigue

These symptoms can appear within 10 to 15 days after being bitten by an infected mosquito. Without prompt treatment, the disease can progress to severe malaria, leading to complications such as organ failure, anemia, or even death.

Plasmodium Species:

There are five species of Plasmodium known to infect humans, causing malaria:

1.   P. falciparum – The most dangerous species, responsible for the majority of malaria-related deaths.

2.   P. vivax – The most widespread species, but generally less deadly.

3.   P. malariae – Less common and typically causes a milder form of the disease.

4.   P. ovale – Rarer and causes a relapsing form of malaria.

5.   P. knowlesi – A zoonotic species primarily found in Southeast Asia, can cause severe disease in humans.

Malaria Vaccines:

1.   RTS,S/AS01 vaccine: Approved by the WHO in 2021, this is the first malaria vaccine that has been shown to reduce malaria cases in children.

2.   R21/Matrix-M vaccine: Approved by the WHO in 2023, this vaccine offers greater efficacy (around 77%) compared to RTS,S.