- Any confirmed or suspected immunosuppressive or immunodeficient state, including HIV infection; asplenia; recurrent severe infections and chronic (more than 14 days) immunosuppressant or other immune-modifying drugs medication (for corticosteroids, this will mean prednisolone, or equivalent, ≥ 0.5mg/kg/day) within the past 6 months (inhaled and topical steroids are allowed).