NEW DELHI — Indian health authorities have intensified surveillance of a widely used rabies vaccine after regulators identified a batch of Abhayrab as substandard and potentially counterfeit, prompting a nationwide alert to state drug-control authorities.

The batch under investigation, identified as KE25012, failed a government laboratory potency test after samples were collected from an unlicensed premises in Delhi. The Central Drugs Standard Control Organisation (CDSCO) has instructed state authorities to closely monitor the movement, distribution and availability of the batch.

Manufacturer Says Seized Vials Were Not Genuine

Indian Immunologicals Limited (IIL), the manufacturer of Abhayrab, has said the seized vials were not produced by the company.

The manufacturer reported multiple differences between the seized samples and its official retained samples, including discrepancies involving packaging, labelling, QR-code verification, artwork, cap colour and other product details. The company said it identified 17 differences between the materials examined by authorities and its authentic records.

The findings have strengthened concerns that the products may have been illegally manufactured or repackaged rather than being genuine Abhayrab vaccines that simply failed a quality test.

Vaccine Failed a Potency Test

The Central Drugs Laboratory in Kasauli examined a field sample connected with batch KE25012 and determined that it did not meet the required potency standard.

Authorities classified the sample as “Not of Standard Quality” and also identified it as misbranded. The investigation is now examining whether the product should legally be classified as a spurious drug.

The distinction is important because the regulator’s findings do not indicate that the manufacturer’s entire Abhayrab production has been declared unsafe.

Instead, the investigation is focused on the specific vials seized from an unauthorized location.

Four People Arrested in Delhi

The suspected counterfeit products were seized during a raid at an unlicensed residential premises in Mukherjee Nagar, Delhi, according to Indian drug authorities.

Delhi Police, along with drug-control officials, conducted the operation earlier this year. Four people have been arrested in connection with the case, while further investigation is continuing.

Authorities are attempting to determine where the questionable vials originated, how they entered the supply chain and whether additional products were distributed.

Batch Was Not Exported

One important point has reduced concerns about an international distribution of the specific batch.

Indian authorities have stated that batch KE25012 was not exported outside India. The regulator has therefore focused its alert on domestic distribution and availability.

This is particularly significant because Abhayrab is also exported internationally and counterfeit versions of the vaccine have previously triggered concerns among overseas regulators.

Second Counterfeit Concern in Less Than Two Years

The latest investigation is not the first time Abhayrab has been associated with counterfeit-product concerns.

Indian Immunologicals notified regulators in 2025 about another suspected counterfeit batch, identified as KA24014. That episode eventually resulted in warnings for travellers who may have received questionable doses in India, including alerts from health authorities in several countries.

The recurrence has increased scrutiny of the vaccine’s distribution chain and the ability of regulators to detect falsified medical products before they reach patients.

Why Rabies Vaccine Authenticity Matters

Rabies is one of the world’s most dangerous infectious diseases once clinical symptoms develop. Vaccination following a potentially infectious animal bite is therefore a critical part of preventing the disease from becoming fatal.

Abhayrab is used for both pre-exposure and post-exposure protection against rabies. The manufacturer’s product information states that the vaccine is intended for people at risk of exposure as well as individuals requiring post-exposure treatment after contact with a suspected rabid animal.

That makes the integrity and potency of every vaccine dose particularly important.

Authorities Issue Nationwide Vigilance Instructions

Following the laboratory findings, the Drugs Controller General of India asked state drug-control authorities to maintain strict vigilance over the identified batch.

Officials have been instructed to monitor its movement and distribution and take appropriate regulatory action wherever questionable stock is discovered.

The approach is intended to prevent potentially counterfeit doses from continuing through legitimate-looking channels.

Genuine Supply Channels Remain Unaffected

Indian Immunologicals has emphasized that authorized supplies of Abhayrab are not affected by the investigation.

The company said it had supplied more than 210 million doses over more than two decades and maintains that the vials seized in Delhi did not match its genuine product records. It is cooperating with authorities investigating the source of the questionable vaccine.

The company has also said that authorized batches undergo government testing before release.

What Patients and Healthcare Providers Should Know

The current investigation concerns a specific batch rather than all Abhayrab vaccines.

Healthcare providers and distributors should therefore verify vaccine stock carefully and follow instructions issued by drug regulators, particularly when dealing with batch KE25012.

The case also highlights the importance of obtaining rabies vaccination through licensed hospitals, clinics and pharmacies rather than unauthorized sellers.

India’s Wider Fight Against Counterfeit Medicines

The Abhayrab case comes amid broader concerns over counterfeit and substandard medicines in pharmaceutical supply chains.

India is one of the world’s major pharmaceutical producers, supplying medicines and vaccines to domestic and international markets. Maintaining confidence in the authenticity of those products is therefore important both for public health and for the country’s pharmaceutical reputation.

Regulatory investigations into suspected falsified products can help identify weaknesses in distribution networks and expose illegal manufacturing operations.

Investigation Continues

Authorities have not yet publicly established the full distribution history of the questioned batch or how many people, if any, may have received the seized products.

The investigation will need to determine the source of the vials, identify everyone involved in their movement and establish whether additional counterfeit stock exists.

For now, India’s drug regulator is urging vigilance while the manufacturer maintains that the seized vaccine was not produced by Indian Immunologicals.

The case serves as another warning that counterfeit medical products can imitate legitimate medicines closely, making regulatory surveillance and verification essential for protecting patients.