DIPHTHERIA VACCINE

Diphtheria vaccine protects children against diphtheria. The diphtheria vaccine is usually given in one injection that also contains tetanus and acellular pertussis (whooping cough) -- DTaP.

Immunisations for Infants and Children <7>

Simultaneous immunisation against diphtheria, tetanus, and pertussis during infancy is recommended. Combination vaccines contain diphtheria and tetanus toxoids and either whole-cell pertussis antigens (DTwP) or acellular pertussis antigens (DTaP). Neither DTwP nor DTaP pertussis vaccine is licensed for persons 7 or more years of age. DTwP vaccine is no longer available in the United States.

Three brands of DTaP currently are approved for use and are available in the United States. Whenever possible, the same brand of DTaP vaccine should be used for all doses of the vaccination series; however, any licensed DTaP vaccine may be used to continue or complete the vaccination series if the type of vaccine previously administered is not known or the type of vaccine used for earlier doses is not available.

Immunisation for infants and children up to the seventh birthday consists of five doses of DTaP vaccine. The first three doses are usually given at ages 2, 4 and 6 months, the fourth dose at age 15-18 months, and the fifth dose at age 4-6 years. The fifth dose is not necessary if the fourth dose was given after the child's fourth birthday.

Three�and preferably four�doses of DTaP are necessary for protection against diphtheria, tetanus and pertussis. Travellers should be advised to complete as many doses as possible of the primary series before travelling. If an accelerated schedule is required to complete the series of DTaP vaccine, the schedule may be started as soon as the infant is 6 weeks of age, with the second and third doses given 4 weeks after each preceding dose (Table 8-3). The fourth dose should not be given before the child is age 12 months and should be separated from the third dose by at least 6 months. The fifth dose should not be given before the child is age 4 years. Interruption of the recommended schedule or delay in doses does not lead to a reduction in the level of immunity reached on completion of the primary series. There is no need to restart a series regardless of the time that has elapsed between doses. For infants and children age <7> Immunisations for Children 7 or More Years of Age, Adolescents, and Adults

Children >7 years of age, adolescents, and adults should receive the adult formulation of ttanus and diphtheria toxoids (Td) whenever either tetanus or diphtheria toxoid is indicated (Tables 8-2 and 8-3; no pertussis vaccine is licensed for use in adults). Anyone >7 years of age who has not received a primary series against tetanus and diphtheria should receive three doses of Td; the first two doses should be given 4-8 weeks apart and the third dose 6-12 months after the second. Two doses of Td received at intervals of at least 4 weeks can provide some protection, but a single dose is of little benefit. In the rare instance when administration of the third dose following a 6- to 12-month interval cannot be ensured, the third Td dose can be given 4-8 weeks after the second dose to complete the primary series. Anyone whose history of primary tetanus and diphtheria vaccination is uncertain should be considered unvaccinated and should receive the three-dose series. Anyone who has received only one or two prior doses of tetanus and diphtheria toxoids should receive additional doses to complete the three-dose series. The first booster dose of Td should be given when the child is 11 or 12 years of age if at least 5 years has elapsed since the last dose of DTaP or paediatric DT. Thereafter, routine booster doses of Td should be given every 10 years.

Adverse Reactions

Local reactions (erythema and induration with or without tenderness) are common after the administration of vaccines containing diphtheria, tetanus, and pertussis antigens. Mild systemic reactions such as fever, drowsiness, fretfulness, and low-grade fever can occur after vaccination with DTaP. These reactions are self-limited and can be managed with symptomatic treatment of Paracetamol (acetaminophen in USA) (paracetamol) or ibuprofen. Reports of moderate to severe systemic events (e.g., fever 40.5�C or higher [105�F or higher], febrile seizures, persistent crying lasting 3 hours or more, and hypotonic-hyporesponsive episodes) have been uncommon after administration of DTaP and they have occurred less frequently among children administered DTaP than those administered DTwP. Swelling involving the entire thigh or upper arm has occurred after the fourth and fifth doses of DTaP. These reactions are also self limited.

Anaphylactic and other serious adverse reactions are rare after receipt of preparations containing diphtheria, tetanus or pertussis components, or a combination of these. Arthus-type hypersensitivity reactions, characterised by severe local reactions, have been reported in adults who received frequent boosters of tetanus or diphtheria toxoids.

Precautions and Contraindications

An immediate anaphylactic reaction to a prior dose of vaccine or vaccine component is a contraindication to further vaccination with DTaP, DT, or adult Td. Encephalopathy not due to another identifiable cause within 7 days of vaccination is a contraindication to further vaccination with a pertussis-containing vaccine.

Moderate or severe acute illness is a precaution to vaccination. Anyone with mild illnesses, such as otitis media or upper respiratory infection, should be vaccinated. Anyone for whom vaccination is deferred because of moderate or severe acute illness should be vaccinated when the condition improves.

Certain infrequent adverse events following pertussis vaccination are considered precautions (not contraindications) to additional doses of pertussis vaccine: a seizure, with or without fever, occurring within 3 days of immunisation; temperature >40.5� C (>105� F) not resulting from another identifiable cause within 48 hours of immunisation; collapse or a shock-like state (hypotonic-hyporesponsive episode) within 48 hours of immunisation, or persistent, inconsolable crying lasting >3 hours and occurring within 48 hours of immunisation. These events have not been proven to cause permanent sequelae. In certain circumstances (e.g., during a communitywide outbreak of pertussis), the benefit of additional vaccination with DTaP may outweigh the risk of another reaction.

Progressive neurologic conditions characterised by changing developmental findings are considered contraindications to receipt of pertussis vaccine. Such disorders include infantile spasms and other epilepsies beginning in infancy. Refer to the American Academy of Paediatrics Red Book for additional information. Infants and children with stable neurologic conditions such as cerebral palsy or controlled seizures should be vaccinated.