Modeling Zika Vaccination Combined With Vector Interventions in DoD Populations

Area of Science:

• Epidemiology
• Mathematical Modeling
• Public Health

Background:

• Zika virus (ZIKV) poses a risk to U.S. military personnel stationed in areas with Aedes mosquito populations.
• ZIKV can cause neurological complications, impacting readiness and health.
• Understanding intervention effectiveness is crucial for protecting military health.

Purpose of the Study:

• To quantify the benefits of interventions, including vaccination, in reducing ZIKV risk on U.S. military installations.
• To evaluate the combined impact of vaccination, personal protective measures (PPM), and mosquito control.
• To inform public health policy for ZIKV outbreak control in military settings.

Main Methods:

• A dynamic transmission model (susceptible-exposed-infected-recovered) was developed to simulate ZIKV spread.
• The model incorporated human-mosquito interactions, mosquito seasonality, and herd immunity.
• Interventions like two-dose vaccination, PPM, and mosquito control were tested against 2016 Puerto Rico data.

Main Results:

• Combining vaccination, mosquito control, and PPM reduced modeled ZIKV cases by 99.9% compared to low-level PPM adherence.
• Vaccination alone showed limited additional benefit due to delayed protection, but adding it to PPM prevented 92.8% of cases over 10 years.
• Effective vector control and PPM were key to significant case reduction.

Conclusions:

• Multi-intervention strategies, particularly combining vaccination with vector control and PPM, are highly effective against ZIKV in military populations.
• Current vaccines can substantially decrease ZIKV incidence when integrated with other control measures.
• Cost-benefit analyses are recommended to guide outbreak control policies and assess economic impacts.