Is there a role for influenza vaccination in cystic fibrosis?

Influenza vaccination is generally recommended to patients with Cystic Fibrosis (CF). Previous studies have shown that influenza infections cause worsening lung functions, disease progression and increase propensity of bacterial infections in CF. However, the clinical evidence in the effectiveness of influenza vaccination in CF is lacking.

This study retrospectively reviewed the influenza vaccination status in the patients with CF and compared the influenza infection rates between the vaccinated and non-vaccinated groups. Finally the factors associated with non-adherence with vaccination were determined.

Nasal swabs were obtained from 63 patients with CF between the age of 6 months to 18 years routinely and during respiratory exacerbations between October 2003 to April 2004. Influenza A and Influenza B were detected using Nucleic Acid Sequence Based Amplification (NASBA). The influenza vaccination status of these patients was retrospectively reviewed.

41 patients (65%) were vaccinated against influenza. For the 22 patients (35%) who were not vaccinated, 7 of them were scared of needles leading to non-adherence. Influenza virus was detected on 5 occasions; 3 were Influenza A (60%) and 2 were Influenza B (40%). 1 virus in the vaccinated group and 4 in the non-vaccinated were detected during the study period (p-value=0.046).

Although the current available evidence to support routine influenza vaccination is limited in CF, this study has shown that such practice may yet play a role in preventing its subsequent acquisition.