Drug Interaction Report

MONITOR: Administration of the smallpox and monkeypox vaccine, which contains a live, attenuated, non-replicating strain of orthopoxvirus, to immunosuppressed patients is generally safe but may be associated with a diminished or suboptimal immunologic response due to antibody inhibition. Such patients may include those who have recently received or are receiving immunosuppressive agents, antilymphocyte globulins, alkylating agents, antimetabolites, radiation, some antirheumatic agents, high dosages of corticosteroids or adrenocorticotropic agents (e.g., greater than or equal to 2 mg/kg/day or 20 mg/day of prednisone or equivalent for 14 consecutive days or more), or long-term topical or inhaled corticosteroids.

MANAGEMENT: It is generally advisable to complete recommended vaccinations, including smallpox and monkeypox vaccine, before starting immunosuppressant or antineoplastic treatment. Clinicians should consult public health authorities and thoroughly assess risks versus benefits prior to administering the smallpox and monkeypox vaccine to immunosuppressed individuals. If the decision is made to vaccinate, titer testing by the Centers for Disease Control and Prevention (CDC) might be considered on a case-by-case basis. Because a correlate of protection has not been established and there is no known antibody titer level that will ensure protection, titer results should be interpreted with caution to avoid providing a false sense of security. Additionally, since immunosuppressed patients might be less likely to mount an effective vaccine response, infections may occur even after full vaccination and outcomes could be particularly severe in these patients, especially following exposure to more virulent orthopoxviruses. Therefore, vaccine recipients might consider avoiding high-risk exposures until after completion of immunosuppressive therapies. Regardless of vaccination status, all individuals who work with orthopoxviruses should wear appropriate personal protective equipment.