Modelling to inform prophylaxis regimens to prevent human rabies

Katie Hampson (1) , Bernadette Abela-Ridder (2) , Omesh Bharti (3) , Lea Knopf (2) , Monique Léchenne (4) , Rolande Mindekem (5) , Arnaud Tarantola (6) , Jakob Zinsstag (4) , Caroline Trotter (7)

1 University of Glasgow
2 OMS / WHO - Organisation Mondiale de la Santé / World Health Organization Office
3 Institut of Health and Family Welfare [Himachal Pradesh, India]
4 Swiss Tropical and Public Health Institute [Basel]
5 CSSI - Centre de Support en Santé Internationale [N'Djamena, Tchad]
6 Institut Pasteur du Cambodge
7 CAM - University of Cambridge [UK]

BACKGROUND: The Strategic Advisory Group of Experts (SAGE) Working Group on rabies vaccines and immunoglobulins was established in 2016 to develop practical and feasible recommendations for prevention of human rabies. To support the SAGE agenda we developed models to compare the relative costs and potential benefits of rabies prevention strategies. METHODS: We examined Post-Exposure Prophylaxis (PEP) regimens, protocols for administration of Rabies Immunoglobulin (RIG) and inclusion of rabies Pre-Exposure Prophylaxis (PrEP) within the Expanded Programme on Immunization (EPI). For different PEP regimens, clinic throughputs and consumables for vaccine administration, we evaluated the cost per patient treated, costs to patients and potential to treat more patients given limited vaccine availability. RESULTS: We found that intradermal (ID) vaccination reduces the volume of vaccine used in all settings, is less costly and has potential to mitigate vaccine shortages. Specifically, the abridged 1-week 2-site ID regimen was the most cost-effective PEP regimen, even in settings with low numbers of bite patients presenting to clinics. We found advantages of administering RIG to the wound(s) only, using considerably less product than when the remaining dose is injected intramuscularly distant to the wound(s). We found that PrEP as part of the EPI programme would be substantially more expensive than use of PEP and dog vaccination in prevention of human rabies. CONCLUSIONS: These modeling insights inform WHO recommendations for use of human rabies vaccines and biologicals. Specifically, the 1-week 2-site ID regimen is recommended as it is less costly and treats many more patients when vaccine is in short supply. If available, RIG should be administered at the wound only. PrEP is highly unlikely to be an efficient use of resources and should therefore only be considered in extreme circumstances, where the incidence of rabies exposures is extremely high.

Mots clés: Dose-sparing; Expanded program on immunization; Intradermal; Intramuscular; Post-exposure prophylaxis; Pre-exposure prophylaxis; Rabies immunoglobulin; Regimen

Domaines: Maladies infectieuses

Katie Hampson, Bernadette Abela-Ridder, Omesh Bharti, Lea Knopf, Monique Léchenne, et al.. Modelling to inform prophylaxis regimens to prevent human rabies. Vaccine, 2019, 37 (Supp. 1), pp.A166-A173. ⟨10.1016/j.vaccine.2018.11.010⟩. ⟨hal-02047498⟩