The HPV vaccine is administered at an approximate interval of 1-2 months between the first and second doses. The third injection is given at least six months after the first injection, or at least four months after the second injection. It is up to the doctor to decide whether or not to give the third shot, and generally adolescent girls between the ages of 9 and 14 can receive only two shots. If the vaccination process is interrupted during the three HPV injections, it is not necessary to restart the first injection. There are three types of HPV vaccines: bivalent, quadrivalent and nine-valent, all of which require three injections.