Positivity rates at month 7 for HPV-16 and HPV-18 antibodies measured in cervicovaginal secretions were higher with Cervarix than with Gardasil. The frequency of circulating antigen-specific memory B cells at month 7 was 2.7-fold higher with Cervarix vs. Gardasil for HPV-16 and HPV-18, and the frequency of CD4+ T-cell responses at month 7 was also significantly higher with Cervarix compared with Gardasil for both HPV-16 and HPV-18. These data confirm differences in immunologic response between the two vaccines, Dr. Dubin said.
“Although the importance of these differences is unknown, they may represent determinants of duration of protection against HPV-16/18 and/or protection against nonvaccine types. Disease modeling will help determine how the observed differences in vaccine profiles may translate into differences in public health impact,” he said, adding that the current data “indicate that the GSK HPV vaccine is likely to provide long-lasting protection against cervical cancer.”