What should you know about quadrivalent inactivated influenza vaccine?

A quadrivalent inactivated influenza vaccine trains the immune system to recognise influenza without containing live influenza virus. It is given by injection, while the exact product and recommended timing depend on age, health, local guidance, and the current influenza season. Vaccination reduces the chance of illness but does not protect against every cause of cough or fever.

Inactivated vaccine material cannot cause influenza infection. After vaccination, the immune system builds a response over time. A sore arm, mild tiredness, headache, or a low fever can occur for a short period. These effects usually settle, but a clinician can advise if they are severe, unusual, or persistent. The vaccine does not replace assessment when someone is seriously unwell.

Before the injection, tell the vaccinator about previous vaccine reactions, severe allergies, current illness, pregnancy, and conditions or medicines that affect immunity. Bring any relevant vaccination record if available. Remain where staff advise after the injection and follow local instructions for managing arm discomfort. Ask when the next seasonal dose or review is due, since recommendations can change with age and health circumstances.

Seek emergency help for trouble breathing, swelling of the face or throat, widespread hives, collapse, or severe dizziness soon after vaccination. Contact a clinician for a high or persistent fever, worsening illness, or symptoms that concern you. A respiratory infection after vaccination may have another cause and should be assessed according to its severity.

Ask: Is this vaccine suitable for me? Which product is being offered? What reactions should I expect? When should I delay vaccination because of illness? Do I need another seasonal dose or a different vaccine?