Factors contributing to declination of annual influenza vaccination by healthcare workers caring for cancer patients: An Australian experience

•A declination form program was evaluated to identify factors associated with influenza vaccination.•Minimal patient contact was significantly associated with lower vaccine uptake in staff HCWs.•Self reported reasons for non-vaccination included potentially modifiable and non-modifiable factors.•An ‘upper threshold’ of vaccination using a non-mandatory approach has likely been met. Healthcare workers (HCWs) at an Australian cancer centre were evaluated using a voluntary declination form program to determine factors contributing to declination of annual influenza vaccination. Overall, 1835/2041 HCWs (89.9%) completed a consent or declination form; 1783 were vaccinated and 52 declined. Staff roles with minimal patient contact were significantly associated with lower vaccine uptake (adjusted odds ratio 0.48, 95% confidence interval 0.23–0.99). Reasons for vaccine refusal included personal choice (41%), previous side-effect/s (23.1%), and medical reasons (23.1%). Of these, a large proportion may not be amenable to intervention, and this must be considered in setting threshold targets for future campaigns.