HYDERABAD: India's drug regulator has flagged a batch of widely used rabies vaccine Abhayrab as substandard and potentially spurious after it failed a potency test, a government document seen by Reuters shows.
The finding marks the second time in less than two years that concerns have been raised about counterfeit Abhayrab doses in India, a country that reports nearly 6,000 rabies deaths a year and where the vaccine is a frontline defence against the otherwise nearly always fatal infection.
Indian Immunologicals Ltd has supplied more than 210 million doses of Abhayrab in India and other countries for over two decades and held a 40% share of the domestic rabies vaccine market, it said in December.
In an August 27 letter to state drug regulators, India's Drugs Controller General Rajeev Singh Raghuvanshi asked officials to maintain "strict vigilance" over the movement and distribution of Abhayrab batch KE25012 and take regulatory action, as necessary.
The action came after the government's Central Drugs Laboratory in Kasauli found that a field sample of the vaccine did not meet potency requirements and classified it as "not of standard quality" and a "misbranded" drug, according to the document.
While the sample passed sterility, moisture and identity tests, the laboratory also found significant differences between the sampled product and a retained reference sample of the same vaccine previously submitted by a division of Indian Immunologicals for regulatory testing.
These included discrepancies in labelling, artwork, QR code verification, cap colour, licence details and packaging text.
The regulator said the findings raised concerns about the sample's "identity and authenticity" and warranted investigation into whether it could be a spurious drug under India's Drugs and Cosmetics Act.
Indian Immunologicals and the federal regulator did not respond to multiple requests seeking comment.
Indian Immunologicals had previously notified India's drug regulator in January 2025 that counterfeit Abhayrab doses bearing batch number KA24014 had entered the market. Global health authorities in the United States, Britain and Australia later issued alerts for travellers who may have received the vaccine in India.
At the time, the company said it had not manufactured the counterfeit batch, reiterated that the incident was isolated and said it was not aware of any other counterfeit doses in circulation.
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.
Abhayrab is a human rabies vaccine used for both pre- and post-exposure protection against rabies. It is administered in multiple doses and is also supplied to government immunization programmes in India.
The government document does not state how many doses of the batch now being investigated may have been distributed, nor whether any doses from the flagged batch had been exported or whether foreign regulators had been notified of the latest alert.
Indian Immunologicals exports Abhayrab to more than 40 countries including South Africa, Turkey, Vietnam, Cambodia, Zimbabwe, Thailand and the United Arab Emirates.
