Should i take the three shot hep. b immun. for school?

Dose number depends: Usually 3 vaccine doses are needed for full protection. The normal dose schedule is dose one, followed by second dose at least 4 weeks afterwards and third dose at least 5 months after that dose. There is also an accelerated series which requires a later fourth dose given in one year. To make it more complicated, there is a 2 dose series-recombivax hb- licensed for children & teens ages 11-15.

Hard to say: You say "for school" which does not provide much information. Hep B is a hardy virus that has been known to cause disease by accidental needle stick in a person cleaning out a long abandoned drug house. Anyone with possible exposure to blood in any form during their personal or professional life can benefit. Some schools or health care facilities require it for students/workers.