What should you know about a messenger RNA (mRNA) vaccine?

The vaccine delivers mRNA, a short-lived instruction molecule, into cells near the injection site. Cells use the instructions to make a harmless target protein or protein fragment. The immune system recognises it, develops a response and then breaks down the mRNA. The mRNA does not enter the cell nucleus, where DNA is stored, and it cannot copy itself.

The immune response can cause temporary soreness, tiredness, headache, fever or muscle aches. These effects reflect immune activity and usually settle without special treatment.

Tell the vaccinator about previous vaccine reactions, severe allergies, current illness, pregnancy, immune conditions and medicines. Follow the recommended schedule for the specific vaccine and remain for the observation period advised by the clinic. Rest, drink fluids and use a suitable symptom reliever only if a clinician or pharmacist says it is appropriate for you.

Call emergency services for difficulty breathing, swelling of the face or throat, widespread hives, collapse or severe dizziness soon after vaccination. Seek prompt medical advice for chest pain, shortness of breath, a racing or irregular heartbeat, or symptoms that are severe, worsening or do not settle.

Ask which infection the vaccine targets, which doses are recommended, how your medical history affects timing and which symptoms require urgent assessment.