How long does the mRNA vaccine stay in your body?

mRNA is a short-lived set of instructions. It helps some cells make a harmless piece of a viral protein, which gives the immune system something to recognise. The mRNA is then broken down by normal cellular processes; it does not enter the cell nucleus or alter your genetic code. The immune response can continue after the mRNA has gone.

Use the aftercare instructions supplied with your vaccination and tell a clinician about allergies, pregnancy, immune conditions, or medicines that may affect your plan. Mild short-term reactions can occur. If you are unsure whether a symptom is expected, describe when it began and how it is changing.

Seek urgent help for severe breathing trouble, swelling of the face or throat, fainting, or chest pain. Contact a clinician for symptoms that persist, worsen, or concern you, particularly if you have a heart condition or another relevant health problem.

Ask which mRNA product is appropriate, how your medicines affect vaccination, and what symptoms should prompt urgent assessment after a dose.