People with asthma

Potential benefits in specific high-risk groups

Influenza vaccination is administered at a time of year when viral upper respiratory infections are common. These infections can cause asthma exacerbations, which may happen to occur soon after vaccination. However, influenza infection accounts for only a small percentage of asthma exacerbations; in a study involving children with asthma aged 9-11 years old, influenza infection was identified in only a small number of exacerbations, while the common cold virus was implicated in 80% of reported exacerbations.¹⁴ A recent systematic review examined whether influenza vaccination increased the risk of asthma exacerbations.⁶ The review assessed findings from two large crossover studies using split virus or surface antigen influenza vaccination and found that that the likelihood of an asthma exacerbation immediately following influenza vaccination is very small.^15,16

The systematic review also examined whether influenza vaccination was effective in preventing asthma exacerbations.⁶ There are very limited data from randomised controlled trials that assess the protective effect of influenza vaccination in asthma, but based on available data, the review found that vaccination was not associated with a reduction in asthma exacerbations from influenza infection. In one randomised, double-blind, placebo-controlled trial involving 696 children aged 6-18 years with asthma, pharyngeal swabs positive for influenza were related to 42 asthma exacerbations: 24 in the vaccine group and 18 in the placebo group (p=NS).17 Influenza vaccination did not result in a significant reduction in the number, severity or duration of asthma exacerbations caused by influenza.

Australian recommendations

The Australian Immunisation Handbook¹ states that, in relation to people with asthma, the benefits of vaccination are likely to outweigh the risks, but there is not enough evidence to recommend vaccination in all people with asthma. Recommendation: "The patients most likely to benefit are those with more severe asthma, such as those requiring frequent hospital visits and it is recommended that these receive influenza vaccine annually."¹

Contraindications to influenza vaccination¹

• Severe allergy to eggs, causing an anaphylactic reaction.
   

• Severe allergy to any of the products in the vaccines, causing an anaphylactic reaction.
   

• An illness with fever over 38.5°C. Flu vaccine can be given once the fever and symptoms of the illness have settled down. Flu vaccine can also be given to people if they have a minor illness without a fever.
   

• History of Guillain-Barre Syndrome which first appeared around the time of a flu vaccination.

Please review the product information before prescribing any influenza vaccination.