Association of Pneumococcal Conjugate Vaccination With Severe Acute Respiratory Syndrome Coronavirus 2 Infection Among Older Adult Recipients of Coronavirus Disease 2019 Vaccines: A Longitudinal Cohort Study.

Background: Pneumococcal carriage is associated with increased acquisition and duration of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among adults. While pneumococcal conjugate vaccines (PCVs) prevent carriage of vaccine-serotype pneumococci, their potential impact on coronavirus disease 2019 (COVID-19)-related outcomes remains poorly understood in populations with prevalent immunity against SARS-CoV-2.
Methods: We undertook a retrospective cohort study of adults aged ≥65 years in the Kaiser Permanente Southern California healthcare system who had received ≥2 COVID-19 vaccine doses, comparing risk of SARS-CoV-2 infection between 1 January 2021 and 31 December 2022 among recipients and nonrecipients of 13-valent PCV (PCV13) employing multiple strategies to mitigate bias from differential test-seeking behavior.
Results: The ajusted hazard ratio of confirmed SARS-CoV-2 infection comparing PCV13 recipients to nonrecipients was 0.92 (95% confidence interval [CI], .90-.95), corresponding to prevention of 3.9 (95% CI, 2.6-5.3) infections per 100 person-years. Following receipt of 2, 3, and ≥4 COVID-19 vaccine doses, aHRs (95% CI) were 0.85 (.81-.89), 0.94 (.90-.97), and 0.99 (.93-1.04), respectively. The aHR (95% CI) for persons who had not received COVID-19 vaccination in the preceding 6 months was 0.90 (.86-.93), versus 0.94 (.91-.98) within 6 months after COVID-19 vaccination. Similarly, aHRs (95% CI) were 0.92 (.89-.94) for persons without history of documented SARS-CoV-2 infection, versus 1.00 (.90-1.12) for persons with documented prior infection.
Conclusions: Among older adults who had received ≥2 COVID-19 vaccine doses, PCV13 was associated with modest protection against SARS-CoV-2 infection. Protective effects of PCV13 were greater among individuals expected to have weaker immune protection against SARS-CoV-2 infection.
Competing Interests: Potential conflicts of interest. J. A. L. discloses receipt of research grants and consulting honoraria from Pfizer and Merck, Sharp & Dohme and consulting honoraria from Seqirus and VaxCyte, all unrelated to this research. S. Y. T. reports receipt of research grants related and unrelated to this research from Pfizer. L. R. G., A. A., A. C., L. J., and B. D. G. are employees of Pfizer and may hold stocks or stock options. All other authors report no potential conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed.
(© The Author(s) 2024. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)