What Changes If You're Pregnant, Immunocompromised, or Allergy-Prone

General vaccine guidance shifts for a few specific populations, each for different medical reasons. Individualised medical advice matters most for these groups.

Pregnancy

Certain vaccines are specifically recommended during pregnancy — Tdap and influenza vaccination in pregnancy are widely recommended by major health bodies, since both protect the mother and pass some antibody protection to the newborn during the vulnerable early months before the infant can be directly vaccinated. Live-attenuated vaccines — which use a weakened but still-active version of the pathogen — are generally avoided during pregnancy as a precaution, which is part of why the specific vaccine type matters clinically, not just the disease it targets.

Immunocompromise

People who are immunocompromised — due to certain medical conditions, organ transplant medication, or some cancer treatments — often need individualised vaccine timing and selection, since live-attenuated vaccines can pose a real risk in this population, while inactivated and subunit vaccines are generally still appropriate and often especially important given elevated infection risk. Being immunocompromised isn't always something you already know about — it's worth raising with a doctor if you notice frequent or unusually severe infections, infections that don't resolve the way they normally would or that keep recurring, or frequent fevers without an obvious cause. This is also the population that depends most directly on herd immunity — the population-level protection created when enough people around them are vaccinated — since their own vaccine response may be weaker.

Allergies

A genuine severe allergic reaction to a specific vaccine component (rather than a general worry about vaccines) is a real, medically significant consideration — anyone with a known history of a severe reaction to a vaccine or a specific vaccine ingredient should discuss this directly with a doctor or allergist before further vaccination, rather than either avoiding all future vaccines or proceeding without addressing it.