Open Veterinary Journal, (2025), Vol. 15(5): 1864

Letter to the Editor

10.5455/OVJ.2025.v15.i5.1

The unsung virtue of thermostable anti-rabies vaccine

Krishna Prasad Acharya^1* and Sarita Phuyal²

¹Animal Disease Investigation and Control Division (ADICD), Department of Livestock Services (DLS), Lalitpur, Nepal

²Department of Livestock Services, Central Referral Veterinary Hospital, Kathmandu, Nepal

*Corresponding Author: Krishna Prasad Acharya. Animal Disease Investigation and Control Division (ADICD), Department of Livestock Services (DLS), Lalitpur, Nepal. Email: kpa26 [at] cantab.ac.uk

Submitted: 27/03/2025 Revised: 16/04/2025 Accepted: 26/04/2025 Published: 31/05/2025

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Dear Editor

Vaccination is the most effective tool to protect against rabies (Bucher et al., 2023; Phuyal et al., 2024). Currently, two different types of vaccines, i.e., tissue culture and cell culture vaccines, are available for prophylaxis against rabies in both animals and humans (Abedi et al., 2023). These vaccines require strict maintenance of the cold chain at a temperature of 2°C–8°C during storage, transport, and delivery to ensure that the full titer of the vaccine is retained during administration. No thermostable rabies vaccine exists that can be safely stored and administered at room temperature. The effectiveness of a vaccine depends on several factors, such as its safety and potency, which in turn depend on the maintenance of adequate cold-chain facilities, starting from the point of production to final administration. In the absence of proper cold chain maintenance, the vaccine loses its potency (Shastri, 2013), rendering it ineffective and leaving recipients unprotected. Thus, the maintenance of the vaccine cold chain is a critical component for maintaining the quality of the vaccine to preserve its potency and increase the effectiveness of immunization programs.

However, maintaining vaccine cold chains is challenging in low- and middle-income countries (LMICs), particularly in remote high-risk areas, due to infrastructure limitations, resource constraints, and logistical difficulties (Acharya et al., 2024; Acharya and Phuyal, 2024). These challenges compromise the safety and efficacy of vaccines, making it difficult for recipients to receive fully potent doses. Economic constraints in LMICs further hinder investment in cold chain infrastructures, worsening difficulties in maintaining vaccine potency.

This underscores the urgent need for the development of thermostable rabies vaccines, which would enable resource-limited countries to deliver effective immunization programs and protect vulnerable populations against rabies. Despite this need, the development of thermostable rabies vaccines has been largely overlooked by vaccine developers and funding agencies.

The development of thermostable rabies vaccines that would facilitate effective delivery should be prioritized, particularly in LMICs and remote, high-risk regions where maintaining cold chain facilities is challenging. This would help address the challenges of cold chain maintenance and improve the overall effectiveness of rabies vaccination programs, ensuring high-quality vaccines are administered to those most in need.

Conflict of interest

None to declare.

Authors’ contribution

Both authors contributed equally to this work.

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References

Abedi, M., Haftcheshmeh, S.M., Bashar, R., Kesharwani, P., Samadi, M. and Sahebkar, A. 2023. Rabies vaccine: recent update and comprehensive review of in vitro and in vivo studies. Process Biochem. 124, 201–220; doi: 10.1016/j.procbio.2022.11.011

Acharya, K.P. and Phuyal, S. 2024. New approaches must be taken to control rabies in low- and middle-income countries. Vet. Rec. 195, 258; doi: 10.1002/vetr.4733

Acharya, K.P., Phuyal, S., Oh, J. and Yon, D.K., 2024. Increasing vaccination against rabies in remote regions. Vet. Rec. 195, 254–255; doi: 10.1002/vetr.4728

Bucher, A., Dimov, A., Fink, G., Chitnis, N., Bonfoh, B. and Zinsstag, J. 2023. Benefit-cost analysis of coordinated strategies for control of rabies in Africa. Nat. Commun; doi: 10.1038/s41467-023-41110-2

Phuyal, S., Acharya, K.P. and Yon, D.K. 2024. Antibody titres after vaccination: a missing key to rabies control. Lancet 404, 1192–1193; doi: 10.1016/S0140-6736(24)01504-6

Shastri, D. 2013. Vaccine storage and handling. In textbook of pediatric infectious diseases. Ed., Feigin RD. pp: 493. doi: 10.5005/jp/books/11900_75