Key Terms & Concepts — UPSC Mains
DIVA (Differentiating Infected from Vaccinated Animals)
"A vaccine and diagnostic design principle requiring that a serological test be able to distinguish an animal that was vaccinated from one that was naturally infected, which is essential for a country to certify disease-free status for trade purposes."
DIVA stands for Differentiating Infected from Vaccinated Animals, a critical capability requirement for animal disease vaccines, particularly for diseases with major trade implications such as African Swine Fever and Foot-and-Mouth Disease. The concept addresses a specific diagnostic problem: many vaccines produce antibodies in a vaccinated animal that are serologically indistinguishable from the antibodies produced by a naturally infected animal, so a standard antibody test cannot tell the two apart. Without DIVA capability, a country that vaccinates its livestock loses the ability to demonstrate, through serological surveillance, that it is free of the underlying disease, because vaccinated animals will test positive on standard antibody assays exactly as infected animals would. This matters enormously for international trade, since importing countries and organisations such as the World Organisation for Animal Health (WOAH) require exporting countries to certify disease-free status, typically through surveillance data that DIVA-incompatible vaccination would render unreliable or unusable. A DIVA-compatible vaccine and companion diagnostic test is therefore designed so that vaccinated and infected animals can be reliably distinguished, usually by targeting antibody responses to specific viral proteins present in a natural infection but absent (deleted) from the vaccine strain, or vice versa. Mass deployment of a vaccine without DIVA capability risks compromising a country's ability to certify freedom from disease even after an outbreak has genuinely been controlled, which is why DIVA compatibility is treated as a precondition for responsible large-scale rollout rather than an optional refinement.
A precise, currently testable GS3 veterinary-science and trade concept, directly relevant to India's 2026 indigenous African Swine Fever vaccine and to any future livestock-vaccine rollout with export implications.
- 1 DIVA = Differentiating Infected from Vaccinated Animals: the capability of a test to distinguish vaccinated from naturally infected animals.
- 2 Without DIVA capability, vaccinated animals test the same as infected ones on standard antibody assays.
- 3 Essential for certifying 'disease-free' status to trading partners and to WOAH (World Organisation for Animal Health).
- 4 Mass vaccination without DIVA compatibility can compromise a country's ability to demonstrate disease freedom through surveillance.
- 5 DIVA-compatible vaccines typically use gene-deleted strains, allowing a companion test to detect antibodies present only in natural infection.
- 6 Raised as a key surveillance requirement alongside India's 2026 indigenous African Swine Fever vaccine, developed at ICAR-NIHSAD, Bhopal.
India's 2026 African Swine Fever vaccine, built on a gene-deleted attenuated strain, was flagged as needing a validated DIVA-compatible companion diagnostic before mass rollout, so that vaccination would not compromise India's ability to certify disease-free zones to trading partners.
