Evaluation of the success and impact of human papillomavirus (HPV) vaccine introduction
and collation of key lessons learnt in low and middle-income countries (LAMICs) is now
possible given the number of recent HPV vaccine pilots, or ‘demonstration projects’, and
national programmes. Results may be useful for countries that have not yet commenced
implementation of the HPV vaccine and may also be generalizable to future introductions of
other pre-adolescent and adolescent vaccines.
This PhD addresses four aspects of HPV vaccine introduction: 1) barriers to adherence to
multi-dose vaccine schedules, 2) the potential impact of the HPV vaccine on human
immunodeficiency virus (HIV) acquisition, 3) the potential impact of HPV vaccine introduction
on other health services, and 4) lessons learnt and recommendations for HPV vaccine
implementation in LAMICs.
A systematic review of the published literature on factors influencing multi-dose vaccine
adherence in adolescents was conducted. The paucity of published data from LAMICs
meant that no geographical restriction was set in the search terms. The majority of research
included in the synthesis originated in the United States of America (USA), where race,
insurance status and parental healthcare seeking behaviour were found to be predictors of
vaccine schedule completion. As vaccination programmes in older children become more
established in LAMICs, more research is needed on factors influencing adherence in these
settings.
The association between HPV infection and subsequent HIV acquisition was assessed in a
nested case-control study using stored cervical samples from previous study cohorts of
Tanzanian and Ugandan women. In contrast to previous observational studies that have
found an association between HPV infection and HIV acquisition in men and women, we
found no evidence of an association between HPV infection, clearance or persistence, and
subsequent HIV acquisition. This precluded the calculation of an estimate of the potential
population attributable fraction for the effect of HPV infection (and vaccination) on HIV
incidence.
Data from health facility register books and interviews with health workers in two regions of
Tanzania were analysed to examine the potential impact of HPV vaccination introduction
through a demonstration project in Northern Tanzania in 2014 on the provision of routine
primary health services. A controlled before-after analysis was carried out on count data of
consultations at facilities involved in HPV vaccine delivery in Kilimanjaro Region, and control
facilities in a neighbouring region. Interviews with health workers provided important
contextual information. There was no evidence that the number of consultations at the health
facilities fell during campaign weeks in intervention facilities compared to control facilities.
Utilisation of the health facilities was highly variable. Interviews indicated that the quality of
care provided at the facility during vaccination campaigns might be affected by staff
absence.
Lessons learnt from 37 LAMICs with at least one year of experience in HPV vaccine delivery
were collated from 41 published articles, 124 pieces of unpublished literature, and 27 key
informant interviews. Recommendations were formulated in 7 key themes: preparation,
communication, delivery, coverage achievements, sustainability, value of demonstration
projects and common pitfalls. Lessons were consistent across world regions and included
the importance of collaboration during planning between the ministries of health and
education, strategies to respond to rumours and challenges encountered during delivery.
Key findings were disseminated widely and stimulated on-going supplemental research.
There is now a large evidence base to support the rationale for HPV vaccine introduction
and its successful delivery in LAMICs, which currently suffer the heaviest burden of cervical
cancer disease in the world. To date, HPV vaccine delivery in low resource settings has
achieved high coverage and experienced fewer barriers than expected. It is clear that if
funding is available, LAMICs can effectively introduce the HPV vaccine nationally and
prevent a high burden of a major and serious disease in women