Significantly Reduced Genoprevalence of Vaccine-Type HPV-16/18 Infections among Vaccinated Compared to Non-Vaccinated Young Women 5.5 Years after a Bivalent HPV-16/18 Vaccine (Cervarix®) Pilot Project in Uganda

PLoS One. 2016 Aug 2;11(8):e0160099. doi: 10.1371/journal.pone.0160099. eCollection 2016.

Abstract

The objective of this study was to determine the prevalence and some predictors for vaccine and non-vaccine types of HPV infections among bivalent HPV vaccinated and non-vaccinated young women in Uganda. This was a comparative cross sectional study 5.5 years after a bivalent HPV 16/18 vaccination (Cervarix®, GlaxoSmithKline, Belgium) pilot project in western Uganda. Cervical swabs were collected between July 2014-August 2014 and analyzed with a HPV genotyping test, CLART® HPV2 assay (Genomica, Madrid Spain) which is based on PCR followed by microarray for determination of genotype. Blood samples were also tested for HIV and syphilis infections as well as CD4 and CD8 lymphocyte levels. The age range of the participants was 15-24 years and mean age was 18.6(SD 1.4). Vaccine-type HPV-16/18 strains were significantly less prevalent among vaccinated women compared to non-vaccinated women (0.5% vs 5.6%, p 0.006, OR 95% CI 0.08(0.01-0.64). At type-specific level, significant difference was observed for HPV16 only. Other STIs (HIV/syphilis) were important risk factors for HPV infections including both vaccine types and non-vaccine types. In addition, for non-vaccine HPV types, living in an urban area, having a low BMI, low CD4 count and having had a high number of life time sexual partners were also significant risk factors. Our data concurs with the existing literature from other parts of the world regarding the effectiveness of bivalent HPV-16/18 vaccine in reducing the prevalence of HPV infections particularly vaccine HPV- 16/18 strains among vaccinated women. This study reinforces the recommendation to vaccinate young girls before sexual debut and integrate other STI particularly HIV and syphilis interventions into HPV vaccination packages.

MeSH terms

  • Adolescent
  • Coinfection
  • Cross-Sectional Studies
  • Female
  • Genotype
  • HIV Infections / epidemiology
  • HIV Infections / microbiology
  • Human papillomavirus 16 / drug effects*
  • Human papillomavirus 16 / genetics
  • Human papillomavirus 16 / immunology
  • Human papillomavirus 18 / drug effects*
  • Human papillomavirus 18 / genetics
  • Human papillomavirus 18 / immunology
  • Humans
  • Immunization Programs / organization & administration
  • Mass Vaccination*
  • Papillomavirus Infections / epidemiology*
  • Papillomavirus Infections / immunology
  • Papillomavirus Infections / prevention & control*
  • Papillomavirus Vaccines / administration & dosage*
  • Pilot Projects
  • Prevalence
  • Syphilis / epidemiology
  • Syphilis / microbiology
  • Uganda / epidemiology
  • Young Adult

Substances

  • Papillomavirus Vaccines
  • human papillomavirus vaccine, L1 type 16, 18

Grants and funding

This work was supported by project research grant Dnr: SWE-2010-146/348-2013-6172 from Swedish International Development Cooperation Agency (SIDA) to Dr. Vanja Berggren (PhD), the second author. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.