Do not administer IV. Postpone administration in patients w/ acute severe febrile illness. Temp ≥40°C; collapse or shock-like state; persistent, inconsolable crying lasting ≥3 hr, occurring w/in 48 hr of vaccination or convulsions w/ or w/o fever, occurring w/in 3 days of vaccination. Thrombocytopenia or bleeding disorders. Immunosuppressed patients. Syncope (fainting) may occur. Protective immune response may not be elicited in all vaccinees. Lactation. Defer pertussis immunization in childn w/ progressive neurological disorders including infantile spasms, uncontrolled epilepsy or progressive encephalopathy.