Uttarkashi-strain based goatpox vaccine provides inadequate protection against lumpy skin disease in cattle.

Lumpy skin disease (LSD) remains a major threat to Indian cattle, causing significant economic and production losses. After a widespread outbreak in 2022, LSD incidence declined in 2023–2024, but by mid-2025, new outbreaks emerged across several states following the monsoon season, highlighting the continued vulnerability of Indian cattle. Since 2021-22, India has implemented annual mass vaccination with the heterologous goatpox vaccine for LSD control; however, frequent reports of LSD cases prompted an evaluation of its field effectiveness. Field investigations were conducted in October 2025 in Rajasthan across 18 farms in five districts, covering 8930 cattle. Overall, the Uttarkashi strain–based goatpox vaccine demonstrated low field effectiveness (21.7%), with similar LSD occurrence in vaccinated (11.2%) and unvaccinated (14.3%) cattle. Partial protection was noted in Udaipur and Rajsamand districts, but the vaccine showed no effectiveness in Balotra and Hanumangarh districts. Notably, cattle older than three years, whether vaccinated or not, were largely unaffected, whereas animals under three years (born after the 2022 outbreak) showed comparable disease incidence regardless of goatpox vaccination status, suggesting that the low LSD incidence in 2023–2024 seems to reflect residual natural immunity from the 2022 outbreak rather than the effect of goatpox vaccination. Field immunogenicity studies demonstrated that the goatpox vaccine generates low antibody titres and insufficient cell-mediated immunity, the principal defense against LSD, whereas LSD-specific vaccine induced markedly higher antibody levels and robust cellular immune responses. In conclusion, Uttarkashi-strain based heterologous goatpox vaccine provides only limited protection against LSD in cattle, highlighting the need to phase out the use of goatpox vaccine and adopt a homologous, LSD-specific mass vaccination strategy in India.