Uman Big is given as an intramuscular (into the muscle) injection to prevent hepatitis B in the following cases: • in case of accidental exposure in people who have not been vaccinated against the hepatitis B virus; including those whose vaccination is incomplete or status unknown; • in haemodialysed patients (patients whose kidneys have failed and who rely on a blood purification technique called haemodialysis), until vaccination has become effective; • in the newborn of a hepatitis B virus carrier-mother; • in subjects who did not show an immune response after vaccination (and for whom a continuous prevention is necessary due to the continuous risk of being infected with hepatitis B.