What should you know about Moderna mRNA flu vaccine?

Messenger RNA, or mRNA, carries temporary instructions that cells can read to make a harmless piece of a target virus. The immune system responds to that piece and builds recognition, then the mRNA is broken down. It does not enter the cell nucleus or alter a person’s genetic code. It also cannot cause influenza because it does not contain a live influenza virus.

Protection develops after the immune system has had time to respond and may not prevent every infection. The aim is to reduce the risk of serious illness; the exact product, schedule, age eligibility, and availability depend on current local guidance.

Tell the vaccinator about previous severe allergic reactions, a past reaction to a vaccine, current illness, pregnancy, immune conditions, and medicines that may affect your care. Bring your vaccination record if available. After the injection, remain where staff advise so an immediate reaction can be treated.

A sore arm, tiredness, headache, muscle aches, or a mild fever can occur for a short time. Rest, drink fluids, and use only medicines suitable for you. The vaccine cannot cause flu, but you can still catch influenza before protection develops or from a different circulating strain.

Get emergency help for trouble breathing, swelling of the lips or throat, widespread hives, fainting, or sudden severe weakness after vaccination. Contact a clinician for symptoms that are severe, worsening, or not settling, or for a high fever with confusion or breathing problems. A mild injection-site reaction is usually managed with observation and supportive care.

Ask which influenza vaccine is recommended for your age and health history, when protection should be expected, and whether another vaccine or a later appointment is more suitable. Ask how to manage a previous vaccine reaction and which symptoms warrant urgent help.