- Subjects will be excluded if they take/have taken chronically high doses of immunosuppressants or other immunemodifying drugs within six months before vaccination, or immunoglobulins or blood products within three months before vaccination, or any investigational product within 30 days before vaccination, have a history of influenza infection since previous vaccination, or if subjects have acute or chronic clinically significant disease or an immunosuppressive/deficient condition, or have contra-indications to influenza vaccination