For those of you who want to know more about the HPV vaccine, you may want to order the audio of the NVIC presentation, “Gardasil Vaccine: Informed Consent?” by Diane Harper, MD, MPH, MS. Harper has worked in all aspects of HPV associated diseases, specifically cervical cancer prevention. She is the leading international expert on HPV vaccines and has worked with both Merck and GSK to develop Gardasil and Cervarix.
Before Harald zur Hausen identified HPV as the cause of cervical cancer in 1976, it was the most common cancer in the world, with a rate of 50 cases per 100,000 women. Today, cervical cancer is the fifth cause of death among women in developed countries with a rate of three cases per 100,000 women, but it is still epidemic in developing countries.
Seventy percent of HPV infections resolve within one year; 90 percent resolve within two years. Only 10 percent of infections will persist and 50 percent of these will be cancer precursors.
Of those who get cervical cancer, 50 percent never got a pap smear and ten percent had a pap more than five years before. Mass screening programs for HPV infection have had dramatic effects. Finland saw a 75 percent drop in cervical cancer when women participated in mass screening. When 70 percent of women in a society participate the rate of cervical cancer drops.
There are risks associated with a pap smear, however, including the stress and anxiety of screening, of abnormal results, of false positive results and of the treatments. There are also possible relationship traumas from the diagnosis of sexually transmitted disease (STD). The treatments, colposcopy and biopsy of the cervix, increase the risk of preterm delivery, low birth weight, premature rupture of the membranes and cesarean birth.
The vaccines, Cervarix and Gardasil, are highly effective against most types of HPV viruses, but not all of them; Merck is working on a supplemental vaccine. Coverage requires three doses of the vaccine and is costly⎯$375 for the series. No efficacy trials in girls under fifteen years of age have been done. The duration of efficacy is unknown for all recipients. On the package inserts, Gardisal publishes efficacy of five years and Cervarix publishes 7.5 years. According to Harper, “If HPV vaccines are not effective for at least 15 years, then no cervical cancer is prevented, only postponed.”
In general, the vaccine has proven safe for most women, but results from the Vaccine Adverse Events Reporting System (VAERS) indicate that 29 percent of vaccine recipients feel dizzy and faint. Thirteen cases of Guillain Barre’ have been reported to VAERS, and thirty-two deaths. The risk of adverse events to HPV vaccine is 7 events per 100,000 vaccinated.
At this time, the HPV vaccine may reduce the incidence of HPV, but not cervical cancer. There will be no substantial decrease in cervical cancer until 70 percent are vaccinated. Screening alone is as effective as screening with vaccines in preventing HPV infection. Screening is still essential.
