Boostagen should not be administered to individuals with past experience or signs of: hypersensitivity or life-threatening reaction following administration of diphtheria, tetanus or pertussis vaccines or to any components of the vaccine (see Description); any encephalopathy with unknown aetiology such as coma, prolonged seizures, or decreased level of consciousness within 7 days following previous vaccination with any whooping cough vaccine; progressive or unstable neurological disorders, uncontrolled epilepsy or progressive encephalopathy.