Azithromycin modulates murine immune responses to pneumococcal conjugate vaccine and inhibits nasal clearance of bacteria

J Infect Dis. 2004 Nov 15;190(10):1762-6. doi: 10.1086/425038. Epub 2004 Oct 13.


Macrolide antibiotics, including azithromycin, have been implicated in the modulation of host immune responses, independently of their antimicrobial properties. The present work was designed to study the effect that azithromycin has on protective humoral immune responses induced by a 7-valent, polysaccharide, pneumococcal conjugate vaccine (PCV7). By use of a murine vaccination/challenge model, it was found that inoculation with azithromycin led to significantly lower primary antibody responses, decreased recall proliferative responses, and, in nasal cavities, impaired clearance of Streptococcus pneumoniae serotype 14 from the nasal cavities. The results demonstrate that azithromycin can be inhibitory with regard to protective immune responsiveness.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Anti-Bacterial Agents / pharmacology
  • Antibodies, Bacterial / blood*
  • Azithromycin / pharmacology*
  • Colony Count, Microbial
  • Disease Models, Animal
  • Female
  • Heptavalent Pneumococcal Conjugate Vaccine
  • Immunologic Memory
  • Lymphocyte Activation
  • Meningococcal Vaccines / administration & dosage
  • Meningococcal Vaccines / immunology*
  • Mice
  • Mice, Inbred BALB C
  • Nasopharynx / microbiology
  • Pneumococcal Infections / immunology*
  • Pneumococcal Infections / microbiology
  • Pneumococcal Vaccines / administration & dosage
  • Pneumococcal Vaccines / immunology*
  • Streptococcus pneumoniae / growth & development*
  • Streptococcus pneumoniae / immunology*


  • Anti-Bacterial Agents
  • Antibodies, Bacterial
  • Heptavalent Pneumococcal Conjugate Vaccine
  • Meningococcal Vaccines
  • Pneumococcal Vaccines
  • Azithromycin