Doctors have reported an exceptionally rare medical case in which a Covid booster appears to have triggered the return of a dormant tuberculosis (TB) infection in a middle-aged man.

The 47-year-old patient, who was living in India, had a latent TB infection with no symptoms. Five days after receiving a Covid booster shot, he developed intense flu-like symptoms, including fever, exhaustion, and night sweats.

Doctors determined that the vaccine had strongly stimulated his immune system. Instead of responding in a balanced way, his body launched an aggressive inflammatory attack against the hidden TB bacteria. This reaction led to a condition known as tuberculosis immune reconstitution inflammatory syndrome, or TB-IRIS. Researchers say this is the first documented case linked to a Covid booster.

The patient’s medical history was complex. He had recently been diagnosed with rheumatoid arthritis and was taking immune-suppressing medication. After TB was identified and treated, his symptoms initially improved. However, they returned more severely following a third Covid dose.

Doctors treated the inflammation with high-dose steroids, which gradually brought his symptoms under control. He remained on TB medication for more than a year and fully recovered.

Experts stress that this case is extremely uncommon. Vaccines remain highly effective and safe for the vast majority of people, but rare immune reactions can occur, particularly in individuals with underlying conditions.