What is an influenza jab?

Most influenza jabs are injected vaccines made with inactivated virus components, so they cannot give you influenza. Protection develops after the immune system has had time to respond and can change as circulating strains change. The jab is intended to prevent or soften influenza, not to cure an illness already underway. Influenza may cause fever, chills, cough, headache, fatigue and feeling generally unwell. A cough or fever after vaccination can also have another cause, including a separate respiratory infection. Pneumonia involves infection and inflammation in the lungs and needs clinical assessment when breathing or chest symptoms are concerning.

Tell the vaccination provider about previous vaccine reactions, allergies, pregnancy, immune problems and ongoing illness. Wear clothing that allows access to the upper arm. Remain at the clinic for the observation period they recommend. Soreness, redness, tiredness, headache or a mild temperature can follow an injection. Gentle arm movement, rest and fluids may help. Use paracetamol or another medicine only if it is appropriate for you and a pharmacist or clinician has advised you. Keep your vaccination record available for future appointments.

Call emergency services for breathing difficulty, throat or facial swelling, collapse, severe wheezing or confusion after the jab. Arrange prompt medical review for persistent high fever, chest pain, worsening cough, marked weakness or shortness of breath. These symptoms need assessment because they may reflect a serious reaction or an infection such as pneumonia rather than an expected arm reaction. For milder symptoms, contact the vaccination service if they are worsening or not settling.

Which influenza jab is recommended for me? When should I receive it? Can I have it while taking my current medicines? Which reactions are expected, and who should I contact if they continue?