DALLAS -- Some immigration advocates object to requiring girls to be vaccinated for a sexually transmitted virus before they can become legal U.S. residents.

AP

The federal rule, which took effect July 1st, added Gardasil to the list of vaccinations that female immigrants ages 11 to 26 must get before they can obtain green cards.

The series of three shots over six months protects against the strains of the human papillomavirus blamed for most cases of cervical cancer and genital warts.

Attorney Tuyet Duong with the Immigration and Immigrant Rights Program at the Asian American Justice Center says the vaccination is a huge economic, social and cultural barrier to immigrants.

Gardasil costs about $400.

Texas lawmakers last year fought off an order by Governor Rick Perry requiring the shots for sixth grade girls—amid questions about vaccine’s safety, efficacy and cost.