What to know about attenuated influenza vaccine

The weakened viruses are designed to stimulate immune protection in the cooler nasal passages without causing typical influenza. Eligibility depends on age, pregnancy, immune status, certain medical conditions, medicines and the locally available product. An inactivated influenza vaccine may be offered when the live nasal vaccine is unsuitable.

A vaccinator sprays the dose into the nostrils; it is not injected. Nasal immune tissue recognises the weakened virus and develops a response to the influenza strains represented in that season's vaccine. Because the formulation is live, clinical screening differs from screening for an inactivated flu injection.

Temporary nasal congestion, runny nose, headache, reduced appetite or tiredness can follow vaccination. These effects are distinct from influenza illness. The vaccine protects against influenza, not every respiratory virus, so coughs and colds can still occur after it is given.

Mention pregnancy, significant immune suppression, close contact with someone who is severely immunocompromised, asthma or recent wheezing, previous severe vaccine allergy, and medicines including antivirals used against influenza. Also report a blocked nose or current illness because the team may alter the timing or choose another formulation.

Breathe normally while the spray is administered; deep inhalation is not required. If you sneeze immediately afterward, tell the vaccinator and follow their advice rather than requesting an extra dose yourself. Keep a record of the product and date, and check whether another dose is recommended for your circumstances.

Seek emergency care for breathing difficulty, swelling of the face or throat, widespread hives, severe weakness or collapse after vaccination. Contact a clinician if wheezing develops, fever is high or persistent, symptoms worsen instead of settling, or you are concerned about a reaction in a child or medically vulnerable person.

Ask whether the nasal live vaccine is appropriate for your age and health history, whether any current medicine affects timing, and whether an inactivated flu vaccine would be preferable. Confirm expected after-effects and what to do if the nose is very congested on vaccination day.