Pneumonia vaccine response in individuals with Down syndrome at three specialty clinics

Am J Med Genet C Semin Med Genet. 2023 Dec;193(4):e32070. doi: 10.1002/ajmg.c.32070. Epub 2023 Oct 20.


Individuals with Down syndrome (DS) have been particularly impacted by respiratory conditions, such as pneumonia. However, the description of co-occurring recurrent infections, the response to pneumococcal immunization, and the association of these was previously unknown. We screened individuals with DS using an 11-item screener and prospectively collected pneumococcal titers and laboratory results. We found that the screener did not successfully predict which individuals with DS who would have inadequate pneumococcal titers. Thirty four of the 55 individuals with DS (62%) had abnormal pneumococcal titers demonstrating an inadequate response to routine immunization. In the absence of a valid screener, clinicians should consider screening all individuals with DS through the use of pneumococcal titers to 23 serotypes to assess vaccine response.

Keywords: Down syndrome; pneumonia; trisomy 21; vaccination.

MeSH terms

  • Antibodies, Bacterial
  • Down Syndrome* / complications
  • Humans
  • Pneumococcal Vaccines / therapeutic use
  • Pneumonia*
  • Streptococcus pneumoniae


  • Antibodies, Bacterial
  • Pneumococcal Vaccines