Background: The introduction of rotavirus vaccine (RVV), pneumococcal conjugate vaccine (PCV) and human papillomavirus vaccine (HPVV) has been slow in Pacific Island Countries, particularly among middle-income countries. To assist decision-making on the simultaneous introduction of these three vaccines, cost-effectiveness and budget impact evaluations were undertaken in Samoa, Tonga, Tuvalu and Vanuatu, using locally relevant data.
Methods and findings: A proportionate outcomes model was used to evaluate vaccine introduction in each country from a health systems perspective, using country-specific data supplemented with regional and global estimates. A 10-year vaccination program was modelled from 2021, with costs and outcomes (disability-adjusted life years [DALYs]) summed over a life-time horizon and discounted at 3%. Vaccine dose costs were based on Pan American Health Organization (PAHO) Revolving Fund prices, with lower-priced products also explored. Introduction of all three vaccines in all countries could prevent over 1,000 deaths over the lifetimes of the vaccinated cohorts. The cost per DALY averted at PAHO Revolving Fund prices ranged from 42% to 73% of the per capita gross domestic product (GDP) in each country, and 15% to 58% for lower-priced vaccines. The budget impact ranged from 359% (Samoa) to 1,368% (Vanuatu) of the 2019 vaccine budgets, and 149% (Samoa) to 775% (Vanuatu) for lower-priced vaccines. Cost-effectiveness results were most sensitive to disease burden, discount rate, vaccine efficacy, and program costs. A limitation of our study is the reliance on data from Fiji to inform disease burden, as availability of country-specific data was limited.
Conclusions: With development partner support, introduction of HPVV, PCV and RVV may represent good value for money in Samoa, Tonga, Tuvalu and Vanuatu, depending on willingness to pay thresholds. However, inclusion of these three vaccines will place considerable burden on immunisation budgets. Financial sustainability requires increases in immunisation budgets and negotiation of affordable vaccine prices. This analysis provides evidence of the benefit of introducing new vaccines, but shows the importance of affordable pricing to ensure sustainability for small Pacific Island countries.
Copyright: © 2026 Carvalho et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.