Some parents and health officials object to standardized vaccinations for teenagers to protect against the sexually transmitted disease human papillomavirus, which is the leading cause of cervical cancer, the Newark Star-Ledger reports. Although two leading vaccine candidates are in the final stages of clinical testing, some health advocates and parents are "already concerned" about requiring the vaccination for young children because they worry that children would interpret it "as a green light to have sex," according to the Star-Ledger (Silverman, Newark Star-Ledger, 4/3). Both GlaxoSmithKline and Merck, Sharp & Dohme, the U.K. subsidiary of the pharmaceutical company Merck, have developed vaccines against HPV that are being tested in thousands of women around the world to confirm the effectiveness and safety of the vaccines. The companies are competing to get their products approved. GSK plans to file for regulatory approval for its vaccine, called Cervarix, in Europe in 2006 (Kaiser Daily Reproductive Health Report, 12/6/04). Merck plans to apply for FDA approval for its expanded HPV vaccine in late 2005 (Kaiser Daily Reproductive Health Report, 11/2/04). Merck might attempt to convince states to require the vaccine for all 12-year-old children before they can enter school, and GSK plans to recommend its vaccine for girls as young as age 10, according to the Star-Ledger. However, the introduction of the vaccines "promises to be anything but routine," as public health officials, pharmaceutical companies and parents "gea[r] up for a heated debate about the finer points of cancer prevention, health care costs and teenage sex," according to the Star-Ledger (Newark Star-Ledger, 4/3).