Development of experimental pneumococcal vaccine for mucosal immunization

PLoS One. 2019 Jun 28;14(6):e0218679. doi: 10.1371/journal.pone.0218679. eCollection 2019.


Streptococcus pneumonia is an important human pathogen that causes various severe diseases such as pneumonia, otitis and meningitis. Vaccination against S. pneumoniae is implemented in many developed countries. The presently used vaccines are safe, well tolerated but relatively expensive and require modification due to the immunological changes of the epidemic strains. This paper describes the development of a new pneumococcal vaccine candidate for immunization on mucosal surfaces. For this purpose the antigens of chimeric protein PSPF, previously suggested for an injectable S. pneumoniae vaccine, were expressed on the surface of the live probiotic strain Enterococcus faecium L3. Experiments on laboratory mice vaccinated with live bacteria demonstrated the appearance of the specific IgA and IgG which provide protection against the lethal S. pneumoniae infection.

MeSH terms

  • Animals
  • Antibodies, Bacterial / metabolism
  • Antigens, Bacterial / genetics
  • Antigens, Bacterial / immunology
  • Antigens, Bacterial / metabolism*
  • Bacterial Proteins / metabolism
  • Enterococcus faecium / genetics
  • Enterococcus faecium / physiology
  • Female
  • Immunoglobulin A / metabolism
  • Immunoglobulin G / metabolism
  • Mice
  • Pneumococcal Infections / immunology
  • Pneumococcal Infections / prevention & control*
  • Pneumococcal Vaccines / administration & dosage*
  • Pneumococcal Vaccines / immunology
  • Probiotics / administration & dosage*
  • Recombinant Proteins
  • Streptococcus pneumoniae / immunology*
  • Trans-Activators / genetics
  • Trans-Activators / metabolism*


  • Antibodies, Bacterial
  • Antigens, Bacterial
  • Bacterial Proteins
  • Immunoglobulin A
  • Immunoglobulin G
  • Pneumococcal Vaccines
  • Recombinant Proteins
  • Trans-Activators

Grant support

The authors received no specific funding for this work.