India will soon have an advanced vaccine against malaria. In a major scientific breakthrough, the Indian Council of Medical Research (ICMR) has developed an innovative recombinant, chimeric multi-stage malaria vaccine that could transform malaria prevention and control efforts in India and globally.
Named AdFalciVax, the vaccine has been developed to offer both protection against Plasmodium falciparum infection in humans and interruption of community transmission, unlike the existing two vaccines that can partially prevent infection in humans but cannot stop transmission in the community.
The novel vaccine developed by Regional Medical Research Centre (RMRC), Bhubaneswar, one of the constituent institutes of ICMR, is now ready for technology transfer to manufacturers or organisations for production, clinical trials and its commercialisation. Preliminary trials on animal models have been highly successful.
The pre-clinical validation of the vaccine has been conducted in collaboration with National Institute of Malaria Research (NIMR), another constituent institute of ICMR, and National Institute of Immunology (NII), New Delhi, an autonomous research institute of the Department of Biotechnology, Government of India.
A dual-stage game changer
Unlike the currently available WHO-recommended vaccines - RTS, S/AS01 (Mosquirix), and R21/Matrix-M which have shown efficacies ranging between 33% and 67%, AdFalciVax promises dual-stage protection. It will not only shield people from contracting the deadliest strain of malaria but also prevent its spread within communities, considered an essential factor in breaking the chain of transmission.
Dr Susheel Singh, scientist-D at RMRC, said AdFalciVax deploys a full-length PfCSP (circumsporozoite protein), a key surface antigen of P falciparum, for broader immune protection. It also incorporates a novel fusion of Pfs230 and Pfs48/45 proteins to induce potent transmission-blocking antibodies.
“The new vaccine can prevent human infection and interrupts transmission in the community, thereby tackling two critical developmental bottlenecks in the malaria parasite's life cycle,” Dr Singh said.
The RMRC researchers said the vaccine has been developed using advanced protein engineering techniques and it leverages Lactococcus lactis, a safe bacterial host system, for antigen production.
Additional director general of ICMR and director of RMRC Dr Sanghamitra Pati said preclinical trials conducted on mice showed robust and long-lasting immunity, even when exposed to 10,000 dual-transgenic Plasmodium berghei parasites engineered to express P falciparum antigens.
“The immune protection lasted over four months post-booster dose, which translates to more than a decade of protection in humans. The vaccine was administered with safe alum-based adjuvants and showed no adverse reactions,” said Dr Pati. Senior scientist Dr Subhash Singh was also a key contributor to the development of the vaccine.
High stability at low cost
The uniqueness of AdFalciVax over existing vaccines is its pharmaceutical stability. The formulation remains potent for over nine months at room temperature, doing away with the need for expensive cold chain logistics, which continue to be a long-standing challenge in vaccine distribution, especially in remote and under-resourced regions.
The vaccine is also highly cost-effective, with an estimated production cost of just `20 per dose. The current vaccines are priced between `250 and `830 per dose. The affordability of the newly developed vaccine could make mass immunisation programmes significantly more viable.
ICMR has now invited expressions of interest from eligible firms and manufacturers for technology transfer and commercial-scale production. The vaccine is expected to go for clinical trial stages soon and potentially be rolled out for public use in the next few years. However, the efficacy during the clinical trials will be the key.