Tdap
百日咳、白喉、破傷風混合疫苗（Tdap）
The vaccine pregnant women need in every pregnancy to protect newborns from whooping cough. Also the 10-year adult booster most HK adults forget.
Boostrix · Adacel
What is it?
Tdap protects against tetanus, diphtheria, and pertussis (whooping cough).
The most important use of Tdap in HK today is maternal vaccination during each pregnancy. Maternal antibodies cross the placenta and protect the baby in the months before the baby's own vaccines kick in.
Tdap is the adult formulation; DTaP is the childhood version. Both are inactivated vaccines.
HK Department of Health recommendation
Pregnant women (HK CHP recommendation since 2019): one dose of Tdap in every pregnancy, ideally between weeks 16-32. Repeat in every subsequent pregnancy.
Children (HKCIP): DTaP-IPV-Hib at 2, 4, 6 months with booster at 18 months. Tdap-IPV booster at Primary 1 and Primary 6.
Adults: Td or Tdap booster every 10 years. After a dirty wound: catch-up if last dose >5 years ago.
International reference (US CDC)
US CDC recommends Tdap for all pregnant women each pregnancy (27-36 weeks), and Td or Tdap boosters every 10 years for adults.
Schedule
Pregnancy: 1 dose of Tdap each pregnancy, ideally weeks 16-32.
Children (HKCIP): DTaP-IPV-Hib at 2, 4, 6, 18 months. Tdap-IPV at Primary 1 and Primary 6.
Adults: Td or Tdap every 10 years.
HK-registered products
| Brand | Manufacturer | HK Reg No. |
|---|---|---|
| Boostrix · Tdap (adult/adolescent) | GSK | |
| Adacel · Tdap (adult/adolescent) | Sanofi |
Side effects
Common: sore arm, mild fever, tiredness, headache. Lasts 1-2 days. Tdap is well-tolerated in pregnancy with extensive safety data.
Common myths
Myth: The pertussis vaccine isn't safe in pregnancy.
Reality: It is. Tdap has been used in pregnancy in the US, UK, Australia, and many other countries for over a decade with no increased risk of complications. HK CHP's recommendation aligns with this evidence.
Myth: If I got Tdap in my last pregnancy, I am covered for this one.
Reality: Antibody levels drop within months. Each pregnancy needs its own Tdap dose so each baby is protected.
Where to get it
- Pregnant women: see your obstetrician or GP
- Children: automatic under the Childhood Immunisation Programme
- Adults: GP for the 10-year booster
Sources
- HK CHP — Maternal pertussis vaccination recommendation · HK Centre for Health Protection (HK)
Related vaccines
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