Residual Disparities in US Adults Hospitalized due to All-Cause Pneumonia Following Implementation of Childhood 13-Valent Pneumococcal Conjugate Vaccine in National Immunization Program.

BACKGROUND

Use of 13-valent pneumococcal conjugate vaccine (PCV13) has reduced the burden of pneumococcal disease among both children and adults. Research has indicated that some population subgroups have benefited more than others. This study estimated rates of inpatient all-cause pneumonia among US adults by age, race, comorbidity profile, and household income (HHI), before and after universal recommendation for PCV13 in children and targeted recommendation for use in adults.

METHODS

A retrospective observational study was conducted using Optum's de-identified Clinformatics Data Mart Database (2007-2019). Adults aged ≥18 years were stratified by age, race, comorbidity profile (low-risk, at-risk/high-risk), and annual household income. Inpatient all-cause pneumonia episodes were identified via relevant International Classification of Diseases (Ninth and Tenth Revisions) codes. Rates per 100 000 person-years and incidence rate ratios (IRRs) were calculated for the pre-PCV13 (2008-2009), peri-PCV13 (2010-2012), post-PCV13#1 (2013-2016), and post-PCV13#2 (2017-2019) periods.

RESULTS

Among 38.7 million US adults, inpatient all-cause pneumonia rates decreased from the pre-PCV13 to post-PCV13#2 period among all age groups (eg, 72.9 to 38.2 among 18- to 49-year-olds and 1621.8 to 1326.0 among ≥75-year-olds). Irrespective of age, rates generally decreased from the pre-PCV13 to post-PCV13#2 period within subgroups defined by race, comorbidity profile, and HHI; the greatest relative reductions were observed among persons aged 18-49 years. During the post-PCV13#2 period, the highest rates of inpatient all-cause pneumonia persisted in Black adults, at-risk/high-risk adults, and adults with HHI <$100 000.

CONCLUSIONS

Despite reductions in inpatient all-cause pneumonia following pediatric PCV13 introduction, residual disparities persist for Black, at-risk/high-risk, and low- and middle-income adults. Strategies to reduce persistent disparities in disease burden among affected adults should be considered and implemented.