- Occurrence of any of the following adverse event after a previous administration of a DTP vaccine :- hypersensitivity reaction to any component of the vaccine; - encephalopathy of unknown aetiology occurring within 7 days following previous vaccination with pertussis-containing vaccine; - fever ≥ 40 °C (axillary temperature) within 48 hours of vaccination not due to another identifiable cause; - collapse or shock-like state within 48 hours of vaccination; - convulsions with or without fever, occurring within 3 days of vaccination.