An immune system response to a foreign substance

A pathological response of the immune system

प्रतिरक्षा प्रणाली की एक रोगसूचक प्रतिक्रिया

English Usage: He experienced an severe immunologic reaction after the medication.

Hindi Usage: उन्हें दवा के बाद एक गंभीर प्रतिरक्षा प्रतिक्रिया का अनुभव हुआ।