Prioritizing COVID-19 vaccination efforts and dose allocation within Madagascar

Area of Science:

• Epidemiology
• Mathematical Modeling
• Public Health

Background:

• Limited COVID-19 vaccine availability in low and middle-income countries (LMICs) necessitates strategic allocation.
• The COVID-19 Vaccines Global Access (COVAX) initiative aims to ensure equitable vaccine distribution.
• Madagascar requires prioritization schemes to maximize benefits from limited vaccine supplies, considering geographic and delivery constraints.

Purpose of the Study:

• To develop and simulate mathematical models for SARS-CoV-2 transmission dynamics in Madagascar.
• To evaluate various COVID-19 vaccination allocation strategies, focusing on geographical prioritization.
• To assess the impact of initial population susceptibility and prior infection testing on vaccination outcomes.

Main Methods:

• Mathematical modeling of SARS-CoV-2 transmission.
• Simulation of diverse geographical vaccination allocation strategies.
• Sensitivity analysis for initial susceptibility and prior infection testing.

Main Results:

• Vaccine distribution based on elderly population or total population size showed greater mortality reduction than case-based allocation.
• The effectiveness of strategies was slightly reduced in regions with high prior disease burden but rankings remained similar.
• Rapid prior immunity testing could significantly reduce mortality, contingent on delivery capabilities.

Conclusions:

• Subnational vaccination strategies prioritizing population size or elderly demographics are effective in reducing COVID-19 mortality.
• These findings support the equitable distribution principles of the COVAX initiative at a global scale.