How does childhood immunisation work?

A vaccine gives the immune system information about a germ without causing the full illness in the usual way. Immune cells make a specific response and retain memory, allowing a quicker response when that germ is encountered.

Some vaccines use an inactivated germ or selected material; others use a live attenuated form that has been weakened. The product and timing depend on the infection, the child’s age, previous doses and local recommendations. Protection may build over time and some vaccines require more than one dose.

Keep the child’s immunisation record available and discuss missed or delayed doses with a healthcare professional. Tell the vaccinator about allergies, previous reactions, current illness and medicines before the appointment.

After vaccination, mild soreness, tiredness or a short-lived fever can occur. Offer fluids, comfort and the advised dose of any medicine; do not give a product unless it is suitable for the child and you understand the instructions. Immunisation helps prevent illnesses such as whooping cough, diphtheria, poliomyelitis and rotavirus infection.

Get urgent help for trouble breathing, swelling of the face or throat, collapse, marked drowsiness, or a seizure after vaccination. Contact a clinician promptly if fever is concerning for the child’s age, persists, or comes with poor drinking, repeated vomiting or unusual behaviour.

Ask which vaccine is due, what infection it prevents, which reactions are expected, and when protection develops. Confirm the next dose, what to do after a missed appointment, and which symptoms require medical advice.