There's plenty of conflicting advice on the internet about vaccinations but here's the official (NHS) site about health risks (and the relevant vaccinations required to protect against them) when travelling to Tunisia: http://www.fitfortravel.nhs.uk/destinations/tu nisia.htm
none. i was in tunisia 2 years ago and there is not a problem!! i telephoned the tunisian embassy in london to ask and they said you do not need any vaccinations to travel to tunisia.