Early immunogenic response to intradermal, subcutaneous, and intramuscular rabies vaccination in cattle and buffaloes: a field study.

Rabies is a fatal zoonotic disease of major global health significance and continues to cause substantial economic losses in livestock in endemic regions, particularly in countries like India where surveillance and reporting remain limited. Preventive vaccination is the most effective means of reducing bovine rabies risk; however, practical considerations such as dose optimization and administration route require further evaluation under field conditions. This study assessed the early humoral immune response to post-exposure rabies vaccination delivered through different routes in cattle and buffaloes on four farms in Punjab, India. A total of 40 bovines were enrolled and allocated into four vaccination groups: cattle vaccinated subcutaneously (SC, 1 mL), buffaloes vaccinated intradermally (ID, 0.2 mL), cattle vaccinated with a low-dose ID regimen (0.1 mL), and buffaloes vaccinated intramuscularly (IM, 1 mL). All animals received a five-dose regimen on days 0, 3, 7, 14, and 28. Serum samples collected on day 28 were analysed for virus-neutralizing antibodies using the Rapid Fluorescent Focus Inhibition Test (RFFIT). Antibody titers differed significantly among vaccination groups (Kruskal–Wallis, p < 0.0001). The 0.1 mL intradermal regimen in cattle (Group 3) elicited the highest immune responses (median 32 IU/mL), which were significantly greater than those observed in cattle receiving subcutaneous vaccination and buffaloes receiving intradermal or intramuscular regimens (p < 0.01). Buffaloes vaccinated intramuscularly (Group 4) showed moderate titers (median 16 IU/mL) and responded significantly better than buffaloes vaccinated intradermally (Group 2) (p < 0.05). Pre-immune controls remained uniformly low, validating the study design. Overall, the reduced-dose intradermal vaccination strategy in cattle outperformed conventional routes.