Oct. 23, 2009 -- Researchers say injections of human papillomavirus (HPV) vaccine apparently hurt less than people may think.
University of North Carolina, Chapel Hill scientists, reporting in the online journal Vaccine, say anecdotal accounts and news stories have stressed the side effects of the HPV vaccine, including reports of painful injections.
The researchers say health care professionals are concerned that these reports may keep young women and others from getting the vaccine or completing the three-dose series, which is recommended.
The HPV vaccine administered during the study period was Gardasil, which protects young women from strains of the virus that cause a majority of cervical cancers and genital warts. Only about 37% of adolescent girls in the U.S. who are eligible for the shots have initiated the three-dose series.
The researchers conducted surveys in 2008 with parents of girls aged 11-20 living in areas of North Carolina with elevated cervical cancer rates who had received at least one shot of HPV vaccine.
Parents reported that pain at the time of HPV vaccination was less frequent and less severe than tetanus or meningococcal vaccines. Compared to all other vaccines received by their daughters, 69% of parents reported that HPV vaccine caused their daughters the same amount of pain or discomfort at the time of the shot. Seventeen percent reported that they experienced less pain from the HPV vaccine, and 12% reported it caused more pain.
"These findings may be important to increase HPV vaccination coverage," write the researchers, who include Paul L. Reiter, PhD, of the University of North Carolina's Gillings School of Public Health.
"Some stories about HPV vaccine side effects and pain have been downright scary," Reiter says in a news release. "However, most parents in our study reported their daughters experienced the same amount of pain or even less pain from the HPV vaccine compared to these other vaccines."
The team reports it found that parents who reported that daughters who completed the series of shots reported pain from the shots just as often as those who were late for subsequent doses.
The findings could increase the number of young women who start and finish the vaccine series by dispelling the myth that the shots are painful, says Noel T. Brewer, PhD, senior investigator of the study.
"It's important for parents and health care providers to be aware of these findings," Brewer says in the news release. "Doctors and parents can now make better informed decisions about giving adolescent girls HPV vaccine."
The main message of the study: "Getting the HPV vaccine hurts less than you think," Brewer says.
HPV Vaccine vs. Other Vaccines
The study was done by telephone interview of 229 parents in five North Carolina counties.
The study found that:
- 65% of parents reported their daughters suffered some pain or discomfort after receiving an HPV vaccine, with more reported at time of injection than in the hours and days that followed.
- Few parents said their children experienced moderate or severe pain at the time of injection or afterward.
- Parents were more likely to report their daughters suffered a higher level of pain or discomfort from tetanus booster shots and meningococcal vaccines.
- More parents reported pain at the time of tetanus shot or meningococcal vaccine than the HPV vaccine.
"While many parents in our study reported their daughters experienced pain or discomfort after receiving HPV vaccine, the reported pain was less frequent and less severe than that associated with other adolescent vaccines and did not affect completion of the HPV vaccine regimen," the researchers write.
The researchers urge health care providers to inform parents and their daughters that pain from the HPV shots has been reported as being similar to or less than the discomfort from other adolescent vaccines.
One researcher, Jennifer Smith of the UNC Lineberger Comprehensive Cancer Center, reported receiving research grants or contracts, honoraria, or consulting fees in the last four years from GlaxoSmithKline and Merck. GlaxoSmithKline makes Cervarix, a vaccine recently approved to prevent cervical cancer in girls and young women. Merck manufacturers Gardasil, recently approved to prevent genital warts in boys and men.
Brewer acknowledges receiving a research grant from Merck on men's attitudes toward HPV, but received no honoraria or consulting fees from Merck or GlaxoSmithKline.