Protective Immunity to Streptococcus pneumoniae

S. pneumoniae causes severe diseases in millions and kills about 1 million children under the age of 5 year each year. Despite their effectiveness, current vaccines against S. pneumoniae target only selected capsular serotypes.

The high cost and limited serotypical coverage, added by serotype replacement, have led to efforts to find novel approaches that target all strains of S. pneumoniae

We work to examine if upper aerodigestive tract exposure to S. mitis induces a state of immunity that modulates carriage state and infection by S. pneumoniae. Our group recently reported serotype-independent protective effects of S. mitis against S. pneumoniae infection in a mouse model. 


Our goal is to develop S. mitis into a novel commensal-based vaccine that will offer a safe, efficacious, low-cost, and broad protection against S. pneumoniae infections. 


We are currently focusing on (1) to investigate the exact immune mechanisms leading to protection, (2) to study how these compare with the effects provided by current vaccines, (3) to examine whether the recently discovered S. mitis natural isolates that express pneumococcal serotypes will enhance the immunization effect provided by S. mitis, and (4) to extend the study to include a feasibility experiment in humans that will pave the way for future testing in phase 1 trials.

Project Progress

Our group has pioneered studies that propose a universal live commensal vaccine against S. pneumoniae. The vaccine is based on S. mitis, a bacterium closely related to S. pneumoniae. S. mitis expresses a majority of proteins found in S. pneumoniae, thus representing a new vaccine that would have the potential to target all S. pneumoniae. Because S. mitis is a commensal, our approach can circumvent the risks inherent to vaccines that use selected or genetically engineered versions of the causative pathogen.

Project leader

Project leader: Professor Fernanda Petersen, UiO

Project coordinator and supervisor

Sudhanshu Shekhar, researcher UiO, (immunology)

Project supervisor

Roger Junges, postdoc UiO (molecular biology)

Current PhD

Navdeep Kaur Brar

Previous PhDs and Postdoctoral fellows

Håkon V. Rukke, PhD
Sudhanshu Shekhar, postdoctoral fellow
Rabia Khan, postdoctorate fellow
Stian Engen, PhD
Gro Herredsvela Rørvik, PhD

Current Funding


Previous Funding

Norwegian Research Council

Previous Partners

Professor Karl Schenk, UiO

Professor Jeremy Brown, Centre for Respiratory Reserch, Department of Medicine, University College London
Professor Marco Oggioni, Department of Genetics, University of Leicester

Professor Daniela Ferreira, Head of m Sciences Department, Professor of respiratory vaccines and infection immunology, LSTM

Dr. Frederica Sallusto, Institute of Research in Biomedicine, Bellinzona, Switzerland 

Previous Clinical Partner

Professor Dag Berild, Department of infectious Diseases, Oslo University Hospital, Oslo


Image may contain: Product, Chemistry.
Previous postdoctoral fellow, Rabia Khan, and current project coordinator and supervisor, Sudhanshu Shekhar, PhD




Published May 18, 2021 2:34 PM - Last modified May 19, 2021 9:50 AM