This article is from the Childhood Vaccinations FAQ, by Lynn Gazis-Sax firstname.lastname@example.org with numerous contributions by others.
According to the labeling, the vaccine is given in a two-dose schedule
to adults 18 years of age and older, the second dose being given 6-12
months after the first. Children and adolescents 2-18 years of age are
given 3 doses. The second dose is given 1 month after the first and
the third dose 6-12 months later. It is administered by intramuscular
injection in the deltoid (upper arm), and can be given with other
vaccines without loss of immunogenicity.