Summary of the safety profile: The type and rate of severe adverse reactions do not differ significantly from the DTwP, rHepB and Hib vaccine reactions described separately.
In an earlier phase 3 clinical trial, 35% of the subjects reported at least one adverse event, out of which commonly reported local adverse events were pain (13%) and swelling (4%) and systemic adverse event was fever (28%).
Description of selected adverse reactions: For this vaccine, mild local or systemic reactions are common. Some temporary swelling, tenderness and redness at the site of injection together with fever may occur in a small number of cases. With similar pentavalent vaccines occasional severe reactions of high fever, irritability and screaming may develop within 24 hours of administration. Hypotonic-hyporesponsive episodes have been reported. Febrile convulsions have been reported at a rate of one per 12,500 doses administered. Administration of acetaminophen at the time and 4-8 hours after vaccination decreases the subsequent incidence of febrile reactions.
Paediatric population: The national childhood encephalopathy study in the United Kingdom showed a small increased risk of acute encephalopathy (primary seizures) following DTwP immunization.
However subsequent detailed reviews of all available studies by a number of groups, including the United States Institute of Medicine, the Advisory Committee on Immunization Practices, and the paediatric association of Australia, Canada, the United Kingdom and the United States, concluded that the data did not demonstrate a causal relationship between DTwP and chronic nervous system dysfunction in children. Thus there is no scientific evidence that these reactions have any permanent consequences for the children.