PHILADELPHIA (CBS) – School students in Pennsylvania must now have some extra vaccinations before the next school year.

Students will now have to prove they have received two doses of the chicken pox and the mumps vaccines before entering school in Pennsylvania in September.

Until now, only one dose of each was needed, according to Heather Stafford, division director for immunizations at the Pennsylvania Department of Health.

She says the new regulations also mean more shots for 7th graders.

“It also includes an additional one-dose requirement for seventh graders only for a tetanus- diphtheria- acellular pertussis-containing vaccine, called T-DAP, and also for a meningitis vaccine,” Stafford told KYW Newsradio on Tuesday.

She says the changes are needed because some vaccines lose their effectiveness and others have been improved, offering better protection for a longer period of time.

Reported by Lynne Adkins, KYW Newsradio 1060.