Prospective cohort study on the effectiveness of influenza and pneumococcal vaccines in preventing pneumonia development and hospitalization

Joon-Young Song, Jin Soo Lee, Seong Heon Wie, Hyo Youl Kim, Jacob Lee, Yu Bin Seo, Hye Won Jeong, Shin Woo Kim, Sun Hee Lee, Kyung Hwa Park, Ji Yun Noh, Wonseok Choi, Hee-Jin Cheong, Woo Joo Kim

Research output: Contribution to journalReview article

12 Citations (Scopus)


Pneumonia and acute exacerbation of chronic illness are leading causes of influenza-related hospitalization. Therefore, influenza and pneumococcal vaccinations are strongly recommended for adults with comorbidities. Using a hospital-based influenza surveillance system, we performed a multicenter, prospective cohort study of patients visiting emergency rooms with influenza-like illness (ILI) during the influenza epidemic period in 2013 to 2014. Patients aged≤19 years were enrolled, and clinical data were collected. Multivariate analyses were performed to estimate the effectiveness of influenza and pneumococcal vaccination in preventing pneumonia development and hospitalization. During study periods, 2,262 patients with ILI were registered. Among 2,217 patients with available vaccination records, 31.9% (707 patients) and 9.7% (216 patients) had received influenza and pneumococcal vaccines, respectively. Among patients who had been administered a pneumococcal vaccine, 94.4% had received the 23-valent polysaccharide vaccine (PPV23). The adjusted rates of effectiveness of the influenza vaccine for preventing pneumonia development and hospitalization were 64.0% (95% confidence interval [CI]=29% to 81%) and 35.0% (95% CI=12% to 52%), respectively. Pneumococcal vaccination did not reduce pneumonia development or hospitalization. In conclusion, influenza rather than PPV23 vaccination may reduce pneumonia development and hospitalization in patients with preceding ILI.

Original languageEnglish
Pages (from-to)229-234
Number of pages6
JournalClinical and Vaccine Immunology
Issue number2
Publication statusPublished - 2015 Jan 1


ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology
  • Clinical Biochemistry
  • Microbiology (medical)

Cite this