O-38 The effectiveness of the HPV Quadrivalent vaccine in Guyanese women
Author(s):
E Hamilton, A Persaud, O Scott, L Niles
Year of Presentation:
2026
Objective: Assess the effectiveness of the Quadrivalent
HPV vaccine in preventing infection against HPV strains
16 and 18 among women screened under the HPV Voucher
Programme in 2024.
Methods: A retrospective cross-sectional study was conducted, utilising secondary data collected from HPV tests performed on Guyanese women under the HPV voucher programme in 2024. The variables analysed were the vaccination status of women who underwent HPV testing, the proportion of vaccinated women with a positive HPV test, and the prevalence of HPV 16 and 18. Descriptive statistics were used to describe vaccination coverage, doses received, and the distribution of HPV strains 16 and 18.
Results: Of the 12,226 women tested for HPV, 1,437 (12.1%) were vaccinated before testing. Among vaccinated women, 4% received 3 doses, 46% received 2 doses, and 47% received 1 dose. Of the vaccinated HPV positive women, 14 strains were discovered, with HPV 16 accounting for 4.8% and HPV 18, 6.1%, respectively. Of the total vaccinated population tested for HPV, 1.9% (29) tested positive for HPV-16, and 2.7% (39) tested positive for HPV-18.
Conclusion: HPV breakthrough infections were observed among women who reported previous vaccination with the HPV Quadrivalent vaccine. The vaccination history taken demonstrated low uptake of the three recommended doses. The findings suggest that the quadrivalent vaccine was effective in preventing infection with HPV strains 16 and 18 in 98% and 97% of vaccinated women, respectively.