A 7-year-old child, who was bitten by a rabid dog, died Thursday after his rabies vaccine failed in a rare instance in India.

Authorities said the child was bitten by the stray dog 23 days before he died. The child, identified by his first name Anandh, was playing near his house in the southern state of Kerala when the dog pounced on him. The dog bit the boy "under his right eye causing serious injury,” his teacher said, according to The New Indian Express.

The child was rushed to the District Hospital, and the doctors administered the first dose of rabies immunoglobulin, which are antibodies that can fight the virus.

The boy was then admitted to a hospital for treatment to the injury close to his eye and he was discharged from the facility the next day. Additional doses of rabies vaccine were given to the boy on the third day and the seventh day.

“His fourth and final dose of vaccine was slated for October 11 (28th day),” his school teacher reportedly said.

However, on Sunday, the boy got a fever, and his parents rushed him to the same hospital. On Tuesday, he was asked to be moved to Kozhikode Medical College.

Doctors at the facility suspected he was infected by the rabies virus and shifted him to an isolation ward. His blood test came positive. In the early hours of Thursday, the boy was declared dead.

“I have not come across such a case in my career,” district medical officer Mohanan E said, while adding this was a rare case of the rabies vaccine not working. A team of experts was reportedly working to determine the cause of the vaccine failure.

Meanwhile, District Surveillance Officer A.T. Manoj said the child was bitten on the face, scalp, and upper lip, which are considered high-risk areas. He added rabies could develop in such cases despite vaccination, according to The Hindu.

Local authorities said residents thrashed the dog to death when it was spotted again. However, no other dog bites were reported from the area.

The victim was the son of Thomas N.V., a fish seller, and Bindu M.K.

stray dogs
This is a representational image. AFP / Dibyangshu SARKAR