Young women seeking to immigrate to the United States currently are required to be vaccinated against the human papillomavirus, under an amendment to the Immigration and Nationality Act. Under the 1996 amendment, individuals seeking immigrant visas must provide proof of vaccination for all vaccines recommended by the U.S. Advisory Committee for Immunization Practices. This list, which is updated periodically, now includes HPV vaccination for females aged 11–12 years, with catch-up vaccination among those aged 13–26 years. The addition of the HPV vaccine to the list of required vaccines for immigrants was automatic and required by statute, according to Centers for Disease Control and Prevention spokesman Curtis Allen, and was not part of ACIP deliberations when the committee originally recommended use of the HPV vaccine. According to a spokeswoman for Merck, the company was not aware of the immigration policy and did not lobby for that provision.