WHAT'S NEW THIS THURSDAY: MEASURING THE IMPACT OF HPV VACCINATION WORLDWIDE AND IN UGANDA

Tuesday, 29th of January 2013

MEASURING THE IMPACT OF HPV VACCINATION WORLDWIDE AND IN UGANDA

From the online abstracts of the International Papillomavirus Conference held in San Juan, Puerto Rico, Nov-Dec 2012. Vaccination abstracts, three reproduced below, start on page 243 of the weblink noted below. Almost all abstracts are from Australia, Europe and the Americas.

http://www.hpv2012pr.org/HPV2012_PUERTO_RICO_Abstracts_Epidemiology_Public_Health.pdf

Abstract Title: Immunogenicity of the bivalent HPV vaccine among partially vaccinated young girls in Uganda

Presenter: Mahboobeh Safaeian, PhD

Investigators / Collaborators: Mahboobeh Safaeian, Emmanuel Mugisha, Yuanji Pan, Edward Kumakech, Troy Kemp, Jane Cover, Ligia Pinto, D. Scott LaMontagne

Country: United States

Objectives

Recent experience with HPV vaccine implementation in Uganda suggests that high vaccine coverage for all three doses could be achieved; however, maintaining a three dose delivery schedule in low resource settings can be challenging. Previous

investigations of vaccine efficacy and immunogenicity for female populations receiving less than 3 doses suggest that two doses may be sufficient for protection. Our primary objective was to assess non-inferiority of <3 doses to 3 doses; a second objective was to compare antibody levels of 3 and <3 doses to natural infection levels measured amongst young women participants in the Costa Rica HPV Vaccine Trial (CVT).

Method

Young girls who participated in an HPV vaccine demonstration project implemented by the government of Uganda in partnership with PATH (2008-2009) in Nakasongola district in Uganda were eligible for this study. We invited all girls who had received one or two HPV vaccine doses, and selected from those who had received all three doses. We further required at least 24 months post receipt of their last vaccine dose (n1 dose=37; n2 doses=144, n3 doses=195). HPV16 and HPV18 specific antibody levels were measured using an enzyme linked immunoassay (ELISA). We defined non-inferiority as lower bound of the multiplicity-adjusted confidence interval (CI) of the type-specific geometric mean titers (GMT) ratio of greater than 0.5.

Results

Ratio of HPV16 and HPV18 GMTs comparing 2 dose to 3 dose groups were 0.51 (97.5%CI=0.37-0.69), and 0.69 (97.5%CI=0.50-0.96).

Due to small sample size, the primary hypothesis for one dose could not be confirmed. In secondary analysis, HPV16 and HPV18 antibody GMTs were higher in all dose groups in our study compared to naturally infected women from CVT (HPV16natural infection=37 vs. HPV161 dose=234, HPV162 doses=812, HPV163 doses=1608; p-value<0.001). Anti-HPV18 GMTs for 1, 2, 3, dose groups were 85, 274, and 396, respectively, compared to 19 among naturally infected (p-value Uganda 1 dose vs. CVT<0.001).

Implications and Impact

These data suggest that girls who miss one dose of the 3-dose bivalent HPV vaccine developed a strong immune response that should afford protection against infection despite the lower GMT titers compared to three dose recipients. Programmatic efforts should always focus on delivery of all three doses; however, in challenging environments like Uganda, two doses might be easier and less costly to implement. If this regimen is sufficient to adequately protect vaccinated girls from future infections with vaccine-type HPV, low-resource setting may elect to adopt a two-dose schedule, as has been done in British Columbia, Canada, and is being considered by Mexico and Quebec, Canada.

Abstract Title: Influences on parental acceptance of HPV vaccination in demonstration projects in Uganda and Vietnam

Presenter: D. Scott LaMontagne, PhD MPH, FRSPH

Investigators / Collaborators: Sean R Galagan1, Proma Paul2, Lysander Menezes3, and D. Scott LaMontagne4

1 Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA

2 University of Pittsburg, Pittsburgh, Pennsylvania, USA

3 PATH, New Delhi, India

4 PATH, Seattle, Washington, USA

Country: United States

Objectives

To investigate the associations between exposure to communication materials and community influencers and HPV vaccine uptake in demonstration projects in Uganda and Vietnam.

Method

We conducted a secondary analysis of a population-based survey of a representative sample of parents/guardians whose daughters were eligible for HPV vaccine through demonstration projects in Vietnam and Uganda. We determined the association between exposure to various components of communication strategies and HPV vaccine uptake using univariate analysis and logistic regression. Two main aspects of communication strategies were assessed. The first was exposure to messages through interactive (e.g., group meetings or house-to-house visits) and non-interactive channels (e.g., leaflets, informational radio or television spots). The second was the type of community influencers (e.g., health workers, family member, community leader) with whom parents spoke about their decision to have (or not have) their daughter vaccinated. We further assessed different combinations of communication channels and influencers on HPV vaccine uptake by calculating the uptake achieved from each.

Results

Speaking with trained personnel was the communication strategy most strongly associated with HPV vaccine uptake in both Uganda and Vietnam [ORUganda y1 = 5.8 (3.3-10.0), ORUganda y2 =3.5 (2.2-5.5), ORVietnam = 4.3 (2.5-7.4)]. Speaking with other influencers, such as family members, neighbors, or friends, was also strongly associated with vaccine uptake. Except for the first year, when radio spots in Uganda [ORadj = 1.8 (1.0-3.4)] and written materials in Vietnam [ORadj = 2.3 (1.1-4.8)] were slightly associated with uptake, non-interactive communication channels had no discernible association with vaccine uptake. Speaking with community influencers was the strongest predictor of HPV vaccine uptake: among parents who spoke to no one but received communication materials uptake was 61.4%, compared to 92.7% among parents who spoke with trained personnel but did not

receive communication materials.

Implications and Impact

This study provides valuable information for policymakers and vaccination programs set to introduce HPV vaccine in low- and middle-income countries. These data indicate that the people you speak with, rather than exposure to communication materials and activities, are the primary drivers of HPV vaccine uptake in these settings. Therefore, HPV vaccine programs may need to focus on communication strategies that incorporate key community influencers and stakeholders, such as health workers, teachers, family members, and friends, as opposed to targeted delivery of non-interactive messages, such as leaflets and posters.

Abstract Title: HPV vaccine demonstration projects: Learning by doing

Presenter: D. Scott LaMontagne, PhD MPH, FRSPH

Investigators / Collaborators: Vivien Davis Tsu1; D. Scott LaMontagne1

Affiliation: 1 PATH, 2201 Westlake Avenue, Suite 200, Seattle, WA 98121 USA

Country: United States

Objectives

Delivery of the human papillomavirus (HPV) vaccine presents significant challenges to immunization programs, especially in countries with limited health care resources. Using vaccine manufacturer donations, several countries have been able to conduct

demonstration programs. Structured evaluations have enabled some of these projects to produce valuable lessons that can guide national best practices. The GAVI Alliance is now making this opportunity available to additional low-income countries. The objective of this paper is to identify strategies for maximizing what can be learned from HPV vaccine demonstration projects.

Method

Careful review was undertaken of experience from four demonstration projects carried out by PATH in collaboration with ministries of health in India, Peru, Uganda, and Vietnam.

Results

Both how the demonstration project is structured and how it is evaluated have an impact on the potential for deriving useful lessons. In setting up demonstration projects, it is important that they rely on existing immunization programs and health systems.

Site selection is critical to ensure that regions with different characteristics are adequately represented. If different delivery strategies are being considered, demonstration projects offer the chance to test the approaches before going to national scale.

Four critical dimensions for evaluation were identified: vaccine coverage, feasibility of delivery strategies, acceptability, and cost of vaccine delivery. Practical methods for measuring each dimension have been developed and validated. These include

household surveys that gather data on coverage and reasons for acceptance or non-acceptance of vaccine; interviews, record reviews, and observations of health workers to see the impact of vaccine delivery on other health services (feasibility); and ingredients-based costing of both start-up and recurrent costs. Results from the four demonstration projects were used to refine national strategies.

Implications and Impact

A well-designed demonstration project can enable an immunization program to test its strategy in different settings, ensure the right target group is being reached, evaluate the effectiveness of its communication materials, identify potential obstacles or efficiencies, estimate the likely financial requirements, and explore opportunities for integration or coordination with other services for young adolescents. Taking advantage of the opportunity being offered by GAVI to conduct demonstration projects before national rollout of HPV vaccine could help overcome some of the hurdles posed by this life-saving, but challenging, new tool in the cervical cancer prevention arsenal.