The nasal spray is designed to build immunity where flu enters the body, but some young children and those with certain health conditions are offered an injection instead.
For many parents, the annual flu appointment raises the same question: why do children usually receive a nasal spray while adults are more often offered a jab? The answer, according to NHS guidance and clinicians, is not about sparing children from a needle. It is about how the vaccine works and which delivery method gives the best protection for different age groups.
Dr Shruti Nathwani, an NHS GP with paediatric training, said the spray is designed to trigger immunity where flu first enters the body. In simple terms, the vaccine works in the lining of the nose as well as in the rest of the immune system, while the injection mainly prompts antibodies in the bloodstream. Both approaches protect against influenza, but they do so in different ways.
There is one important exception. Some younger children, especially those aged six months to 23 months, are offered an injection instead of the spray. Dr Nathwani said clinical trials in that age group found an unexpected risk of wheezing and higher hospital admissions, which is why the injection is used for them instead. The NHS also says suitability depends on age, health and individual circumstances.
The nasal spray is a live vaccine, though the weakened virus it contains is not the same as catching flu. Most children tolerate it well, but possible side effects can include a runny nose, tiredness, headache or a reduced appetite. The NHS advises that some children should not have the spray, including those under two, those with a history of severe allergic reaction to the vaccine or its ingredients, and some children with severe asthma or a weakened immune system. The guidance has also changed so that an egg allergy is no longer, on its own, a reason to rule out the spray, although vaccination teams should still be told about any allergies.
According to CDC advice, flu vaccination remains important because it reduces the risk of illness, hospitalisation and death, and annual vaccination is recommended for everyone aged six months and over. NHS Scotland and the Government of Jersey say the child flu programme also helps protect families and communities by reducing spread.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
