Modelling to inform prophylaxis regimens to prevent human rabies

Area of Science:

• Public Health
• Epidemiology
• Vaccinology

Background:

• The Strategic Advisory Group of Experts (SAGE) Working Group on rabies vaccines and immunoglobulins was established in 2016.
• Aims to develop practical and feasible recommendations for human rabies prevention.
• Models were developed to compare costs and benefits of rabies prevention strategies.

Purpose of the Study:

• To evaluate the cost-effectiveness of different rabies Post-Exposure Prophylaxis (PEP) regimens.
• To assess the optimal administration of Rabies Immunoglobulin (RIG).
• To determine the economic feasibility of including rabies Pre-Exposure Prophylaxis (PrEP) in the Expanded Programme on Immunization (EPI).

Main Methods:

• Examined various PEP regimens, RIG administration protocols, and PrEP inclusion in EPI.
• Evaluated cost per patient treated, patient costs, and treatment capacity under vaccine scarcity.
• Utilized modeling to compare the relative costs and potential benefits of different rabies prevention strategies.

Main Results:

• Intradermal (ID) vaccination reduces vaccine volume, is less costly, and mitigates shortages.
• The 1-week 2-site ID regimen is the most cost-effective PEP strategy.
• Administering RIG at the wound site uses less product and is more advantageous.
• PrEP within EPI is substantially more expensive than PEP and dog vaccination for human rabies prevention.

Conclusions:

• Modeling insights inform WHO recommendations on rabies vaccines and biologicals.
• The 1-week 2-site ID regimen is recommended for its cost-effectiveness and ability to treat more patients during vaccine shortages.
• RIG should be administered at the wound site if available.
• PrEP is generally inefficient and should only be considered in rare, high-exposure circumstances.