Immunisation in Pregnancy
A 28-year-old woman at 14 weeks of gestation attends the clinic to update her immunisations. She is well, has no allergies, and her rubella IgG is negative. She plans to travel abroad and asks which vaccines she may safely receive during this pregnancy. Which of the following vaccines is contraindicated at this time?
- A.Tetanus, diphtheria and acellular pertussis vaccine
- B.Inactivated influenza vaccine
- C.Hepatitis B vaccine
- D.Measles, mumps and rubella vaccineCorrect
Explanation
Live attenuated vaccines are contraindicated in pregnancy because of a theoretical risk of fetal infection from the vaccine virus, and measles, mumps and rubella vaccine is the classic example, along with varicella, live attenuated influenza, yellow fever and oral polio vaccines. A seronegative woman should therefore be vaccinated immediately after delivery, which is safe including during breastfeeding, and pregnancy should be avoided for 28 days afterwards. Importantly, inadvertent administration of measles, mumps and rubella vaccine in early pregnancy has never been shown to cause congenital rubella syndrome and is not an indication for termination. Inactivated, subunit, toxoid, recombinant and messenger RNA vaccines are safe and several are actively recommended: inactivated influenza vaccine in any trimester, and tetanus, diphtheria and acellular pertussis vaccine between 27 and 36 weeks to transfer antibody that protects the newborn against pertussis. Hepatitis B vaccine is inactivated and is indicated when the woman is at risk, as is respiratory syncytial virus vaccine between 32 and 36 weeks. Yellow fever vaccine, though live, may be given if travel to an endemic area is unavoidable and the risk of disease outweighs the theoretical vaccine risk. Human papillomavirus vaccine is not live but is deferred until after delivery for lack of data. The zoster vaccine now in use is recombinant rather than live, but it is likewise deferred in pregnancy.
Why each option
- A.
- Tetanus, diphtheria and acellular pertussis vaccine is a toxoid and subunit product actively recommended at 27 to 36 weeks to protect the newborn.
- B.
- Inactivated influenza vaccine is safe and recommended in any trimester during influenza season.
- C.
- Hepatitis B vaccine is a recombinant inactivated product and may be given when the woman is at risk.
- D.
- Correct. This is a live attenuated vaccine and is contraindicated in pregnancy; give it immediately postpartum instead.
Reference: ACOG Committee Opinion 741, Maternal Immunization (reaffirmed 2023); CDC Advisory Committee on Immunization Practices, Guidelines for Vaccinating Pregnant Women (2024)
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