Using epidemic modeling to promote more equitable global health policy: The case of pathogen access and benefit sharing
Shoa Moosavi
MS Candidate, Epidemiology of Infectious Disease
Yale School of Public Health
EMD Research Day - April 28, 2025
Note: All data and analyses are preliminary and subject to change.
Background
In response to glaring inequities during COVID-19 pandemic, WHO Member States have proposed several systemic changes meant to ensure more equitable outcomes for future health emergencies. Among these initiatives is the Pandemic Agreement. Members of the Intergovernmental Negotiating Body (INB) reached a consensus in April 2025 and will present their final draft to the World Health Assembly this May for adoption.
However, not all elements of the instrument are finalized. An intergovernmental working group will continue to draft annexes to the agreement, including an annex on a Pathogen Access and Benefit-Sharing (PABS) system, per Article 12 of the Pandemic Agreement. The PABS system is based upon the principle that all states retain sovereign ownership over their own biological materials, including pathogens. However, they also recognize that samples and data from pathogens with pandemic potential are essential to developing medical countermeasures against future threats- including vaccines, therapeutics, and diagnostics.
The PABS system motivates states to share “PABS material” (i.e. samples and sequence data) by tying participation in the system to tangible benefits in the form of the products that are produced from that data. The PABS system allocated a certain percentage of real-time production of medical countermeasures for distribution based on public health need. Under the current draft text, 10% of production is provided for free, and the remaining percentage is provided at affordable prices.
In this study, we use a stochastic, compartmental, SEIRS model to demonstrate the impacts of allocating part of real-time COVID-19 production to eligible countries. In the absence of a codified PABS system, COVAX eligibility is used as a proxy for PABS eligibility. We show the impact on vaccine access, infections, and deaths for the first year of vaccine availability (December 8, 2020 - December 7, 2021).
Results
Vaccine Access
Allocating a percentage of vaccine doses in real-time means PABS-eligible countries receive doses sooner and receive more doses overall.
The PABS system especially helps low-income, fragile, and conflict-affected states who were unable to purchase vaccines.
Here, you can see PABS-eligible countries in order from most to least reliant on doses from the PABS system.