Abstract:
This study aimed to test zona pellucida (ZP) vaccines’ immunocontraceptive efficacy
and safety when formulated with non-Freund’s adjuvant (6% Pet Gel A and 500 Mg Poly(I:C)).
Twenty-four jennies were randomly assigned to three treatment groups: reZP (n = 7) received three
doses of recombinant ZP vaccine; pZP (n = 9) received two doses of native porcine ZP; and Control
group (n = 8) received two injections of placebo. Jennies were monitored weekly via transrectal
ultrasonography and blood sampling for serum progesterone profiles and anti-pZP antibody titres.
In addition, adverse effects were inspected after vaccination. Thirty-five days after the last treatment,
jacks were introduced to each group and rotated every 28 days. Vaccination with both pZP and
reZP was associated with ovarian shutdown in 44% (4/9) and 71% (4/7) of jennies, 118 33 and
91 20 days after vaccination, respectively (p > 0.05). Vaccination delayed the chances of a jenny
becoming pregnant (p = 0.0005; Control, 78 31 days; pZP, 218 69 days; reZP, 244 104 days).
Anti-pZP antibody titres were elevated in all vaccinated jennies compared to Control jennies (p < 0.05).
In addition, only mild local injection site reactions were observed in the jennies after treatment. In
conclusion, ZP vaccines formulated with non-Freund’s adjuvant effectively controlled reproduction
in jennies with only minor localised side effects.
Description:
SUPPLEMENTARY MATERIAL : FIGURE S1: Progesterone concentration of jennies vaccinated with recombinant zona pellucida vaccine (reZP, green lines), native porcine zona pellucida (pZP, red lines), or placebo (Control, black lines) from Day 70 to the day of pregnancy diagnosis. Jennies were vaccinated with three doses of reZP on Days 70, 35 and 0. For both pZP and Control, the primary dose and the booster were administered on Days 35 and 0. FIGURE S2: Effect of antibody titer at Day 35 (D35) on time to ovarian shutdown in the pZP and reZP groups combined. The solid line shows the shutdown rate relative to the mean D35 antibody titer as the reference. The dashed lines show the 95% confidence intervals. FIGURE S3: Effect of antibody titer at Day 35 (D35) on time to pregnancy in the pZP and reZP groups combined. The solid line shows the pregnancy rate relative to the mean D35 antibody titer as the reference. The dashed lines show the 95% confidence intervals.
