The long-term consequences of the HPV vaccine are not known and there have not been any long-term studies. Children in the 9-year-old age group have been monitored for only 18 months, and there have been no studies of the long-term risk of the vaccine itself. Between July 2006 and January 2007, there were 82 reports of adverse events filed with the Vaccine Adverse Event Reporting System ([[VAERS]]) following the receipt of the vaccine.
A study published February 28, 2007 in the Journal of the American Medical Association (JAMA) (<ref>JAMA 297(8):813-819, February 28, 2007) </ref> disclosed that about 3% of all women are ever infected in their lifetime by the particular types of HPV (Types 6, 11, 16, 18) targeted by the vaccine. If generalized to the American female population at large, this would be approximately 5 million women. If generalized to the highest-risk age groups of women, the number of affected American women is probably closer to 2 million.
Merck manufactures the HPV vaccine and sells it for $360 ($120 per shot in a three-shot series). Its package insert explains the limitations of the vaccine and describes its testing for safety and efficacy.<ref>http://www.merck.com/product/usa/pi_circulars/g/gardasil/gardasil_pi.pdf</ref>