People taking any of the following categories of medications are considered severely immunocompromised:
•High-dose corticosteroids—Most clinicians consider a dose of either >2 mg/kg of body weight or ≥20 mg per day of prednisone or equivalent in people who weigh >10 kg, when administered for ≥2 weeks, as sufficiently immunosuppressive to raise concern about the safety of vaccination with live-virus vaccines. Furthermore, the immune response to vaccines may be impaired. Clinicians should wait ≥1 month after discontinuation of high-dose systemic corticosteroid therapy before administering a live-virus vaccine.
•Alkylating agents (such as cyclophos-phamide).
•Antimetabolites (such as azathioprine, 6-mercaptopurine).
•Transplant-related immunosuppressive drugs (such as cyclosporine, tacrolimus, sirolimus, azathioprine, and mycophenolate mofetil).
•Cancer chemotherapeutic agents, excluding tamoxifen but including low-dose methotrexate weekly regimens, are classified as severely immunosuppressive, as evidenced by increased rates of opportunistic infections and blunting of responses to certain vaccines among patient groups. Limited studies show that methotrexate monotherapy had no effect on the response to influenza vaccine, but it did impair the response to pneumococcal vaccine.
•Tumor necrosis factor (TNF) blockers such as etanercept, adalimumab, certolizumabpegol, golimumab, and infliximab blunt the immune response to certain vaccines and certain chronic infections. When used alone or in combination regimens with methotrexate to treat rheumatoid disease, TNF blockers were associated with an impaired response to hepatitis A, influenza, and pneumococcal vaccines. ◦Despite measurable impairment of the immune response, postvaccination antibody titers were often sufficient to provide protection for most people; therefore, treatment with TNF blockers does not preclude immunization against hepatitis A, influenza, and pneumococcal disease. If possible, both doses in the hepatitis A series should be given before travel.
◦The use of live vaccines is contraindicated according to the prescribing information for most of these therapies.
•Other biologic agents that are immunosuppressive or immunomodulatory may result in significant immunocompromise. In particular, certain monoclonal antibodies, such as rituximab or alemtuzumab, are more significantly immunosuppressive, and neither inactivated or live vaccines should be administered for at least 6 months—and perhaps longer—after cessation of therapy with these agents.