Predictors of pneumococcal vaccination among Australian adults at high risk of pneumococcal disease

Background: Although nearly all Australian children are vaccinated against pneumococcal disease, pneumococcal vaccine uptake is low among high-risk adults. This study aimed to identify perceived barriers to pneumococcal vaccination among high-risk adults.

Methods: This paper reports combined data on pneumococcal vaccination collected from three different online, cross-sectional surveys that were administered in Australia between August 2019 and September 2020. Using Poisson regression, we identified characteristics and beliefs associated with self-reported pneumococcal vaccination among adults aged 65 and over or with chronic health conditions.

Results: The weighted estimate for pneumococcal vaccine coverage was 24% for high-risk adults under 65 and 53% for adults aged 65 and over. Nearly half of those under 65 reported they had never heard of the pneumococcal vaccine, while 26% of those aged 65 and over had never heard of the vaccine. Among those under 65, pneumococcal vaccination was associated with high perceived disease susceptibility (PR = 1.97, 95% CI: 1.23, 3.18), not having heard of the pneumococcal vaccine (PR = 0.44, 95% CI: 0.28-0.69), awareness that their chronic health condition puts them at increased risk of pneumonia (PR = 2.44, 95% CI: 1.51-3.98), and having a doctor recommend the vaccine (PR = 3.02, 95% CI: 2.05-4.44). Among adults aged 65 and over, self-reported pneumococcal vaccination was associated with influenza vaccination in the previous 12 months (PR = 4.28, 95% CI: 2.85-6.44) and awareness that they are eligible for free pneumococcal vaccination (PR = 5.02, 95% CI: 2.34-10.77).

Conclusion: Awareness of pneumococcal vaccines was low among adults at high risk of pneumococcal disease, which appears to be contributing to low vaccine uptake. A doctor's recommendation was associated with increased uptake of pneumococcal vaccine, so interventions should be developed to promote pneumococcal vaccine uptake in GP practices.