Now a more efficacious, inexpensive malaria vaccine

Now a more efficacious, inexpensive malaria vaccine

Subject :Science and tech

Section: Biotechnology

Context:

• A malaria vaccine– R21/MatrixM– developed by the University of Oxford, manufactured by the Pune-based Serum Institute of India and tested in a phase-3 trial at five sites in four countries– Mali, Burkina Faso, Kenya, and Tanzania– in Africa was recommended (but yet to be prequalified) by the WHO on October 2.

About the vaccine:

• The Matrix-M component is a proprietary saponin-based adjuvant developed by Novavax and licensed to the Serum Institute for use in endemic countries.

What is Adjuvant?

An adjuvant is an ingredient in a vaccine that enhances the immune system’s response to that vaccine.

Adjuvants help the immune system better recognize what’s in a vaccine and remember it longer, increasing the amount of time that a vaccine may offer protection.

Matrix-M adjuvant is derived from saponins, naturally occurring compounds found in the bark of the Quillaja saponaria tree in Chile. Saponins have a history of medicinal use.

• It is a new vaccine approved for the prevention of malaria in children.
• It is the first malaria vaccine to reach the WHO’s target of 75% efficacy.
• It has already been approved for use in Burkina Faso, Ghana, and Nigeria.
• The vaccine will be rolled out in those African countries in early 2024 and will be available in mid-2024 in other countries.

What is Malaria?

• It is a life-threatening disease caused by parasites that are transmitted to people through the bites of infected female Anopheles mosquitoes.
• There are 5 parasite species that cause malaria in humans, and 2 of these species, Plasmodium falciparum and Plasmodium vivax, pose the greatest threat.
• Malaria is common in tropical areas where it’s hot and humid.
• Children under 5 years of age are the most vulnerable group affected by malaria.

It is mostly found in tropical countries. Four African countries accounted for just over half of all malaria deaths worldwide: Nigeria (31.3%), the Democratic Republic of the Congo (12.6%), United Republic of Tanzania (4.1%) and Niger (3.9%).

Elimination Strategies:

India:

• National Framework for Malaria Elimination (2016-2030)
• Malaria Elimination Research Alliance-India (MERA-India)

Vaccine efficacy of the new malaria vaccine:

• Three countries- Nigeria, Ghana, and Burkina Faso– have already approved the use of the vaccine to immunize children aged less than 36 months.
• The vaccine efficacy at the end of one year in children aged 5-36 months was 75% where malaria is seasonal and 68% where malaria is perennial.
• In children aged 5-17 months, who are more likely to die due to severe malaria, the vaccine efficacy was higher — 79% where malaria is seasonal and 75% where malaria is perennial.
• The higher vaccine efficacy in younger children (5-17 months) compared with older children (18-36 months).
• The vaccine was more efficacious in places where malaria was seasonal than when it was perennial.
• The vaccine efficacy is highest 14 days after the third dose and begins to slowly wane.
• The vaccine efficacy of R21/MatrixM is much higher than the first malaria vaccine — RTS,S/AS01 that has been recommended by the WHO in 2021 — which had a vaccine efficacy of 56% at the end of one year in children aged 5-17 months. According to the preprint, even after four booster shots of the RTS,S/AS01 vaccine, the efficacy was only 58% over five years.
• There was “significantly reduced” parasite load in children who received the vaccine (R21/Matrix-M) that suggests that the vaccine may help reduce malaria transmission, especially when combined with other strategies such as mosquito nets.
• The cost of the R21/Matrix-M manufactured by Serum Institute will be between $2 and $4 per dose.

Source: TH