Some very limited evidence suggests that response to immunisation with live vaccines may be more severe than usual in thepresence of indometacin
Clinical evidence,mechanism, importance and management
A man with ankylosing spondylitis taking indometacin 25mg three times daily had a strong primary-type reaction 12 days after smallpox vaccination. He experienced 3 days of severe malaise,headache and nausea, as well as enlarged lymph nodes. The scab that formed was unusually large (3 cm in diameter) but he suffered no long term ill-effects (See reference number 1). The suggestion was that indometacin alters response of body to viral infections, whether originating from vaccines or not (See reference number 1). This suggestion is supported by case of a child taking indometacin who developed haemorrhagic chickenpox during a ward outbreak of disease (See reference number 2). These appear to be isolated reports,and of little general importance. Note that NSAIDs such as indometacin may mask some of signs and symptoms of infection.
Maddocks AC. Indomethacin and vaccination. Lancet (1973) ii,210–11.
Rodriguez RS,Barbabosa E. Hemorrhagic chickenpox after indomethacin. N Engl J Med (1971) 285, 690.