Akutte overfølsomhedsreaktioner (såsom urticaria, angioødem, bronkokonstriktion, anafylaksi) over for interferon alfa- 2b har sjældent været observeret under IntronA behandling.
Acute hypersensitivity reactions (e.g., urticaria, angioedema, bronchoconstriction, anaphylaxis) to interferon alfa-2b have been observed rarely during IntronA therapy.