Targeted preventive vaccination campaigns to reduce Ebola outbreaks: An individual-based modeling study

Area of Science:

• Epidemiology
• Public Health
• Mathematical Modeling

Background:

• Nonpharmaceutical interventions (NPI) and ring vaccination are standard Ebola outbreak control measures.
• These interventions are often implemented late in an outbreak, facing real-time challenges.
• Preventive vaccination offers a potential complementary strategy for proactive protection.

Purpose of the Study:

• To assess the impact of preventive vaccination strategies.
• To evaluate their effectiveness when combined with NPI and ring vaccination.
• To model Ebola transmission dynamics in the Democratic Republic of the Congo.

Main Methods:

• An individual-based model (IBM) simulating Ebola transmission was developed.
• The model incorporated human contact patterns, movement, and intervention timing.
• Simulations tested preventive vaccination of healthcare workers (HCW), frontline workers (FW), and the general population (GP) at varying coverage and efficacy levels.

Main Results:

• Preventive vaccination of HCW reduced cases, hospitalizations, and deaths by 11–25% compared to NPI + ring vaccination.
• Including FW in vaccination campaigns improved outcomes by 14–38%.
• Extending vaccination to the GP yielded the greatest reduction (21–52%) and flattened epidemic curves, especially early on.

Conclusions:

• Preventive vaccination can significantly decrease Ebola cases, hospitalizations, and deaths.
• This approach helps protect healthcare systems and allows more time for implementing other interventions.
• Proactive vaccination strategies are crucial for mitigating Ebola outbreaks.