Oral Vaccination of Dogs: Systematic review Finds a Strategy for Rabies Elimination

A recent systematic review concludes that integrating oral immunization into national health frameworks as a localized pilot could finally achieve the 70% dog immunity threshold necessary to eliminate the 59,000 annual deaths associated with the 35% global rabies burden found in India, according to a recent study published in the Indian Journal of Community Medicine in February 2025.

Rabies remains a critical public health threat in India, yet achieving necessary vaccination targets is currently impeded by the logistical impossibility of traditional parenteral methods for the nation's 6.2 crore free-roaming dogs (FRDs). Addressing this clinical gap, Dr. Haripriya H and associates from the Department of Community and Family Medicine at the All India Institute of Medical Sciences (AIIMS) Patna aimed to evaluate the feasibility of the oral vaccination of dogs (OVD) strategy by reviewing previous international field trials and its potential integration into the National Action Plan for Rabies Elimination (NAPRE).

Therefore, the systematic review employed a rigorous methodology involving a comprehensive PubMed database search using specific Boolean operators to identify 220 relevant publications, which were subsequently refined to 19 core full-text articles focusing on the practical adoption and outcomes of field trials over the last ten years. The study design prioritized assessing OVD efficacy within roaming dog populations, examining endpoints such as bait acceptance rates and vaccination coverage without the need for the exclusionary and labor-intensive physical restraint required in traditional Capture-Vaccinate-Release (CVR) models.

Key Clinical Findings of the Systematic Review Include:

• Enhanced Coverage: In the study OVD consistently reached inaccessible, aggressive, or shy dog populations that parenteral methods often miss, ensuring a more robust barrier against viral transmission.

• Exceptional Acceptance: International evidence suggests that bait acceptance is remarkably high among roaming dogs, with success rates documented as high as 97.2% in Haiti and 92.9% in Thailand.

• Economic Efficiency: Oral distribution models outperformed traditional methods in cost-effectiveness, significantly reducing the financial and human resource burden compared to labor-intensive capture campaigns.

• Scalable Impact: Evidence shows that combining oral baits with existing door-to-door parenteral strategies resulted in superior total population coverage, which is essential for maintaining the 70% immunity level required for disease eradication.

• Operational Ease: OVD requires significantly less specialized training and fewer personnel than CVR, making it a more viable strategy for large-scale national implementation in resource-limited settings.

The results suggest that implementing mass oral vaccination programs can provide a sustainable, cost-effective pathway to eliminate dog-mediated rabies, potentially managing the 6.2 crore free-roaming dog population more effectively than a CVR campaign that would require 1.1 million vaccinators, thereby moving India closer to its target of zero human rabies deaths by 2030.

Thus, the study concludes clinicians and public health authorities may find value in supporting the integration of oral baiting as a complementary tool alongside traditional parenteral vaccines to enhance community-wide immunity.

While the study acknowledges that factors such as maintaining a consistent cold chain and ensuring the safety of live-recombinant vaccines for non-target species must be addressed, future research focusing on locally produced, cost-effective bait materials could further optimize this promising strategy for diverse geographic regions.

Reference

Prathapan A, Debbarma S, Haripriya H, Pandey S. Oral vaccination of dogs in India as a strategy for elimination of rabies: Scope of implementation. Indian J Community Med 2025;50:413-6.