Co-administration of the broad-spectrum antiviral, brincidofovir (CMX001), with smallpox vaccine does not compromise vaccine protection in mice challenged with ectromelia virus.

•Brincidofovir facilitates vaccination healing more efficiently than cidofovir.•Co-administration of brincidofovir and vaccine does not diminish protective immunity.•Efficacy was recorded when brincidofovir and vaccine was administered up to 2days post-virus challenge.