Re: Specific Antibody Levels at the Cervix During the Menstrual Cycle of Women Vaccinated With Human Papillomavirus 16 Virus-Like Particles

Extract

We read with interest the article by Nardelli-Haefliger et al. (1) in which the authors reported an approximate ninefold reduction in cervical anti-human papillomavirus 16 (HPV16) immunoglobulin (Ig; specific IgG and total IgG and IgA) levels at the time of ovulation in 11 women who received aluminum-free (i.e., adjuvant-free) HPV16 L1 virus-like particle (VLP) vaccine synthesized in a baculovirus system (1). The authors hypothesized that the efficacy of prophylactic HPV16 L1 VLP vaccines may be reduced during the peri-ovulatory phase in women who are not using hormonal contraception.

We recently reported (2) the primary efficacy results of a multicenter, placebo-controlled trial of a prophylactic HPV16 L1 VLP vaccine in 2392 women aged between 16 and 23 years. The HPV16 L1 VLPs were synthesized in yeast and formulated on aluminum adjuvant. In the primary efficacy cohort, the vaccine was found to be 100% effective in preventing persistent cervicovaginal HPV16 infection and related cervical intraepithelial neoplasia for a median of 17.4 months following the completion of vaccination.