Lack of effects on male fertility from a quadrivalent HPV vaccine in Sprague-Dawley rats.
BACKGROUND
Human papillomavirus (HPV) infection is one of the most common sexually transmitted diseases in both men and women. A recently developed quadrivalent HPV vaccine, Gardasil, has been shown to be highly effective in the prevention of several HPV-mediated diseases. The objective of the present study was to evaluate the potential effects of the vaccine on male fertility including reproductive performance, sperm evaluations, and histology of the testes. In addition, anti-HPV antibodies were measured during the study.


METHODS
Group 1 (30 male rats) received the full human dose of vaccine (0.5 mL, ∼200-fold excess based on body weight) by intramuscular injection at 6 weeks, 3 weeks, and 3 days prior to cohabitation. Group 2 males received only 1 dose at 3 days prior to cohabitation. Additional groups (20 male rats each) were administered PBS or Merck Aluminum Adjuvant similarly to Group 1. Ten males in the vaccine-treated groups were bled for immunogenicity assays after each dose. Twenty males per group were mated to untreated female rats. Cesarean sections were performed on Gestation Day 15 or 16. Cohabited males were necropsied and sperm count and motility were evaluated.


RESULTS
There were no unscheduled deaths during the study and no evidence of toxicity in vaccine-treated male rats. The vaccine induced a specific antibody response to the 4 HPV types after each injection. There were no effects on the cesarean-section parameters of females or reproductive parameters of the cohabited male rats, including histomorphology of testes and epididymis, sperm count, and sperm motility.


CONCLUSIONS
These results demonstrate that this quadrivalent HPV vaccine had no detectable adverse effects on routine measures of male fertility in rats.
Wise
L David
LD
Merck Research Laboratories, West Point, Pennsylvania 19486, USA. ld_wise@merck.com
Pauley
Cindy J
CJ
Michael
Bindhu
B
Wolf
Jayanthi J
JJ
D052685:Alphapapillomavirus / Q000276:immunology; D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology; D004822:Epididymis / Q000033:anatomy & histology / Q000187:drug effects / Q000276:immunology; D005260:Female; D005298:Fertility / Q000187:drug effects*; D000068857:Human Papillomavirus Recombinant Vaccine Quadrivalent, Types 6, 11, 16, 18; D008297:Male; D053918:Papillomavirus Vaccines / Q000009:adverse effects* / Q000276:immunology; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D012098:Reproduction / Q000187:drug effects*; D013081:Sperm Motility / Q000187:drug effects*; D013737:Testis / Q000033:anatomy & histology / Q000187:drug effects / Q000276:immunology
D000914:Antibodies, Viral; D000068857:Human Papillomavirus Recombinant Vaccine Quadrivalent, Types 6, 11, 16, 18; D053918:Papillomavirus Vaccines