TdTdap

Td and Tdap are vaccines used to prevent tetanus and diphtheria, with Tdap adding protection against pertussis (whooping cough). The term TdTdap is not a single product; it reflects the choice between giving Td (tetanus and diphtheria) or Tdap (tetanus, diphtheria, and acellular pertussis) as booster doses. Td and Tdap are given as intramuscular injections.

Td is composed of tetanus and diphtheria toxoids and is used as a routine booster every 10 years in adults. Tdap contains the same tetanus and diphtheria components plus acellular pertussis. The pertussis component is especially emphasized for protection of infants and during pregnancy, where pertussis prevention is particularly beneficial.

Immunization schedules vary by age and risk. Children receive DTaP (the pediatric formulation including diphtheria, tetanus, and acellular pertussis) and later transition to Td or Tdap for boosters. In adults, one dose of Tdap is recommended if a person has not previously received it, followed by Td boosters every 10 years if pertussis protection is not required. Pregnant women are advised to receive a Tdap dose during each pregnancy (preferably 27–36 weeks gestation) to protect the newborn. In some situations, such as contact with an infant or outbreak, a Tdap dose may be given even if a prior booster was recent.

Common side effects are mild and include pain, redness, or swelling at the injection site, fever, and fatigue. Serious adverse reactions are rare. Vaccination is contraindicated in individuals with a severe allergic reaction to a previous dose or to any vaccine component, and generally postponed during moderate or severe illness.