The diphtheria vaccine is non-replicating and is made from cell-free purified toxin extracted from C. diphtheriae and converted into diphtheria toxoid. The vaccine is given to adults in combination with tetanus toxoid and inactivated polio vaccine (Td/IPV) in a preparation containing a lower dosage of diphtheria toxoid than preparations designed for use in childhood. The vaccine is given by parenteral administration. The diphtheria vaccine induces protective antitoxin levels in 95% of recipients after three doses, and shows a clinical efficacy of over 97%. The vaccine is well tolerated. Injection site reactions are common but usually self-limited and may occur more frequently following subsequent doses. Fever and other systemic reactions are uncommon. Severe systemic reactions are rare.
The aim of the UK national vaccination programme is to ensure that all individuals receive at least 5 vaccine doses. Td/IPV is recommended for vaccination of those aged ≥10 years. It is also recommended that travellers to epidemic and endemic areas should ensure they are fully vaccinated.