India's drug regulator has flagged a batch of the widely used rabies vaccine Abhayrab as substandard and potentially spurious after it failed a potency test, according to a government document. The vaccine is used for both pre- and post-exposure protection against rabies, is administered in multiple doses, and is also supplied to government immunization programs in India. India records an estimated 5,726 human rabies deaths annually, according to a 2024 study by the Indian Council of Medical Research's National Institute of Epidemiology.

The latest finding marks the second time in less than two years that concerns have been raised about counterfeit doses of the vaccine in India. The manufacturer, Indian Immunologicals Ltd (IIL), said the vials carrying the vaccine's label that were examined by the regulator were not manufactured by the company. The samples were drawn by the Central…