The Indian Council of Medical Research (ICMR) has revealed AdFalciVax, a new malaria vaccine candidate. It targets Plasmodium falciparum, the parasite responsible for most malaria deaths globally. The vaccine is set for further development, human trials, and commercial manufacturing in partnership with private firms. This marks step in malaria control, especially given the limitations of existing vaccines.
Malaria and Its Global Impact
Malaria is a mosquito-borne parasitic disease causing fever, chills, nausea, and severe complications like organ damage and death. It kills around 400,000 people annually worldwide. Africa bears the highest burden, with countries like Nigeria and Tanzania reporting most deaths. India has reduced malaria deaths drastically, but estimates vary between national and global agencies.
Existing Vaccines and Their Limitations
Two vaccines, RTS,S and R21, have been approved recently but offer only about 75% efficacy. They target only one protein of the parasite and require multiple booster doses. Their immune response is short-lived and they use adjuvants that can cause chronic inflammation. These factors limit their effectiveness and widespread adoption.
How AdFalciVax Works
AdFalciVax is a chimeric recombinant vaccine targeting two proteins of Plasmodium falciparum. It uses the circumsporozoite protein (CSP) to block infection in vaccinated individuals by acting on the parasite’s sporozoite and liver stages. It also employs the Pro6C protein, a fusion of Pfs230 and Pfs48/45, which interrupts parasite development inside mosquitoes, reducing transmission in the community.
Advantages Over Existing Vaccines
Unlike RTS,S and R21, AdFalciVax uses full-length CSP proteins, potentially triggering a stronger immune response. Animal studies showed over 90% protection in mice. The vaccine’s immune response may last longer, with three doses protecting mice for over three months, equivalent to about ten years in humans. It contains alum as an adjuvant, which is safer and more stable at room temperature for nine months, easing storage and transport.
ICMR’s Collaboration Terms With Private Sector
ICMR will partner with a private company for clinical trials and commercial production. It will share the vaccine technology but retain intellectual property rights. Any new rights from the collaboration will be jointly held. ICMR will receive 2% royalty from sales. Both parties will share research credits and data ownership.
Limitations and Scope
AdFalciVax is ineffective against Plasmodium vivax, the common malaria parasite in India. The vaccine is still in preclinical stages and requires rigorous human trials before approval. Its success could transform malaria prevention but is currently limited to Plasmodium falciparum.
Questions for UPSC:
- Point out the challenges in developing vaccines for parasitic diseases like malaria and how recombinant vaccines address these challenges.
- Critically analyse the role of intellectual property rights in public-private partnerships in vaccine development with suitable examples.
- Estimate the impact of vaccine storage and transport innovations on immunisation programmes in rural and remote areas of India.
- Underline the relationship between vector control strategies and vaccine development in combating vector-borne diseases like malaria.
