Tdap

Tdap is a combined vaccine that protects against tetanus, diphtheria, and pertussis (whooping cough). It contains tetanus and diphtheria toxoids and acellular pertussis antigens. Tdap is used as a booster for adolescents and adults who completed the childhood DTaP series and as part of maternal immunization to protect newborns.

Indications and schedule: In many countries, a single dose of Tdap is recommended for people roughly aged 11 to 64 years who have not previously received a Tdap booster, replacing one Td booster. Adults who have already completed childhood DTaP and later have not received Tdap should receive one Tdap dose, followed by Td boosters every 10 years. Pregnant women should receive a Tdap dose during each pregnancy, preferably between 27 and 36 weeks gestation, to maximize antibody transfer to the fetus.

Composition and brands: Tdap vaccines include acellular pertussis components along with tetanus and diphtheria toxoids. Brand names include Adacel and Boostrix, and formulations vary by country.

Safety: Common adverse effects are pain, redness, or swelling at the injection site; fever, headache, or fatigue. Serious events are rare. Contraindications include severe allergic reaction to a previous dose or to any vaccine component; moderate or severe acute illness. Precautions include a history of encephalopathy within seven days of a previous pertussis-containing vaccine and a history of Guillain-Barré syndrome within six weeks of a previous tetanus or pertussis vaccine.