SAN DIEGO – Only 8.5% of children and young adults with autoimmune diseases and 9.1% of those without such diseases received one or more doses of the human papillomavirus vaccine, a large analysis of national claims data showed.
"Despite the high efficacy of HPV vaccine in preventing cervical cancer and clinically acceptable safety profile in the general population, the vast majority of patients aged 9-26 in our study cohort with and without autoimmune diseases did not receive the HPV vaccine," Dr. Seoyoung C. Kim said in an interview prior to the annual meeting of the American College of Rheumatology, where the study was presented.
"Patients at high risk of persistent HPV infection should be encouraged to receive the vaccine, although future study is needed to determine the effectiveness of HPV vaccine in patients with autoimmune diseases, particularly those on immunosuppressive drugs," she added.
In 2006 and 2009, two three-dose series HPV vaccines were approved for use in males and females aged 9-26 years. Prior research has suggested that patients with lupus or inflammatory bowel disease or those who take immunosuppressive agents have a higher risk of persistent HPV infection or cervical dysplasia, said Dr. Kim of the division of pharmacoepidemiology and pharmacoeconomics in the department of medicine at Brigham and Women’s Hospital, Boston.
"HPV vaccine has been available for the past several years in the U.S. and in other countries," she said. "As far as we know, there has not been any study looking at the uptake of HPV vaccine in the autoimmune disease population."
Using United HealthCare national claims data for 2005-2012, Dr. Kim and her associates identified patients aged 9-26 years with at least 1 year of continuous enrollment who had at least two autoimmune disease diagnosis codes 7 or more days apart. Vaccination was defined as one or more vaccine codes after 2006, and the researchers accounted for coexisting diseases, use of health care treatments, and geographic regions when assessing vaccine uptake.
Dr. Kim, the study’s senior investigator, reported data for 29,255 children and young adults with autoimmune diseases and 117,020 without. The mean age was 19 years, and 59% were female. Patients in the autoimmune diseases group had a higher number of physician visits, abnormal pap smears, and sexually transmitted diseases, compared with their counterparts without autoimmune disease (all P values less than .01).
Overall, autoimmune disease patients and their counterparts had similarly low uptake of at least one vaccine dose (8.5% vs. 9.1%, respectively; P = .34). The uptake was higher among females in both groups (13.1% vs. 14.1%, respectively; P less than .01), yet fewer than 5% of female patients in both groups completed a three-dose vaccine series (4.7% vs. 4.6%; P = .57). A higher percentage of patients in the Northeast received one or more HPV vaccine doses (16.3% vs. 11.8%; P = .02); otherwise vaccinations were equally distributed from a geographic standpoint.
In a subgroup of female patients who had at least 2 years of follow-up, 20.6% with autoimmune disease and 23.1% without autoimmune disease received at least one vaccine dose. Of those, 53.1% and 51.4%, respectively, completed the series.
"We were generally surprised to see how low the uptake has been in both autoimmune and nonautoimmune populations," Dr. Kim said. She acknowledged certain limitations of the study, including the fact that it was conducting using the claims data from United HealthCare, "so it only captures patients who used the insurance card to pay for the vaccine," she said. "However, given the high cost of the HPV vaccine, this limitation is probably not substantial. We [also] did not have information on race/ethnicity."
Dr. Kim disclosed that she is supported by a grant from the National Institutes of Health. She received a research grant from Pfizer and tuition support for the pharmacoepidemiology program at the Harvard School of Public Health, which is funded by Pfizer, Millennium Pharma, and Asisa.