SAN FRANCISCO — Quadrivalent human papillomavirus vaccine demonstrated effectiveness through 8 years in boys, girls, young and adult women, according to findings presented here during ID Week 2013.
Anna-Barbara Moscicki, MD, department of pediatrics and the Teen Colposcopy Clinic, division of adolescent medicine, University of California, San Francisco, said that quadrivalent HPV (qHPV) vaccine (Gardasil, Merck) continues to demonstrate effectiveness through 6 to 8 years post-vaccination in boys, girls, young and adult women and that no HPV type 18–associated breakthrough disease was observed. Quadrivalent HPV vaccine includes types 16 and 18, as well as HPV 6 and 11.
Currently there are more than 16 studies of post-licensure follow-up, but Moscicki focused on three of these studies during her presentation.
Moscicki said the long-term follow-up program includes approximately 3,000 Nordic young women aged 16 to 26 years when enrolled into the original protocol 015 efficacy study (FUTURE II; 2002-2003) who were subsequently followed through national registries. The program also includes 1,610 Colombian women aged 24 to 45 from the protocol 019 efficacy study (FUTURE III; 2004-2005) and 1, 781 sexually-naïve US boys and girls aged 9 to 15 from the protocol 018 immunogenicity study (2003-2004).
In protocol 019, the women underwent examinations with cytology at 12-month intervals and for protocol 018, examinations with genital and vaginal swabs for HPV DNA in sexually active boys and girls were performed every 6 months.
“Post-licensure studies are going to be extremely important, to help in looking at long-term effectiveness, safety and immunogenicity,” Moscicki said.
The number of years for follow-up for subjects in protocols 015, 019 and 018 subjects was 8, 8 and 6 years, respectively. No breakthrough cases of HPV 6/11/16/18-related genital warts or cervical intraepithelial neoplasia were observed for any of the groups.
According to Moscicki, in protocol 018, there were two episodes of 6-month persistent infection in girls and two in boys, but no lesions were observed. In protocol 015, year 9 seropositivity for HPV 6, 11, 16 and 18 was 98%, 96%, 100% and 91%, respectively in the total IgG Luminex immunoassay. In protocol 019, year 6 IgG seropositivity for HPV 6, 11, 16 and 18 was 88%, 84%, 100% and 82%, respectively.
Year 8 seropositivity against HPV 6, 11, 16, and 18 in the extension of protocol 018 based only on the competitive LIA was 88%, 89%, 97% and 64%, respectively; IgG data are not yet available. The rate of acquiring new sexual partners among males (120.0/100 PY) in protocol 018 was higher than that of females (69.2/100 PY).
No new vaccine-related safety concerns emerged in any population.
“We see within 6 to 8 years of follow-up, the qHPV vaccine remains highly effective against the vaccine-related types and related anogenital disease,” Moscicki said. “Long-term follow-up studies consistently support a safety profile for the vaccine and a follow-up of subjects continues and more data will be available soon.”
For more information:
Moscicki AB. Abstract 639. Presented at ID Week 2013; Oct. 2-6, 2013; San Francisco.
Disclosure: Moscicki serves on a Merck advisory board. One of the study researchers is a Merck employee.