Because of the long incubation period of hepatitis B it is possible for unrecognised infection to be present at the time of immunisation.
ήκιγολοιτια η ίεθωιρηµκετ ιεχέ νεδ ςιεσώτπιρεπ ςέλλοπ εσ Β ςαδιτίταπη