top of page


Validated Inference of Adoption Likelihood

Welcome to VIAL. Dalberg Advisors has built this site as a sharing tool for stakeholders interested in country preferences for different Gavi vaccines. We will update the site as new results and antigens are included.



The methodology

Validated inference of adoption likelihood (VIAL) is a methodology pioneered by Dalberg Advisors to better understand country preferences for different health products. VIAL builds on conjoint analysis and specialized survey questionnaires to map and understand country preferences. We then translate country data into scenario forecasts for products, that enable discussion around the potential future market dynamics of a given antigen. The work is done in service of the Bill and Melinda Gates Foundation and Gavi, the vaccine alliance. 


The work started in November 2018 focusing on vaccines for human papillomavirus (HPV) and pneumococcal conjugate vaccines (PCV). In May 2019 the work was expanded to rotavirus and and cominations of penta/polio/hexa vaccines. 

About Dalberg:

Dalberg Advisors is a strategic advisory firm that combines the best of private sector strategy skills and rigorous analytical capabilities with deep knowledge and networks across emerging and frontier markets. We work collaboratively across the public, private and philanthropic sectors to fuel inclusive growth and help clients achieve their goals.


For any questions regarding the work, please contact:

Wouter Deelder, Partner, Dalberg Advisors,

James Eustace, Associate Partner, Dalberg Advisors,

bottom of page