Comparison of the immunization with a polysaccharide conjugate vaccine and protein antigens in the control of co-colonization with Streptococcus pneumoniae

• Grant number: 16/09427-5
• Support Opportunities: Regular Research Grants
• Start date: September 01, 2016
• End date: February 28, 2019
• Field of knowledge: Biological Sciences - Microbiology
• Principal Investigator: Eliane Namie Miyaji
• Grantee: Eliane Namie Miyaji
• Host Institution: Instituto Butantan. São Paulo , SP, Brazil

Abstract

Streptococcus pneumoniae is an important human pathogen, causing diseases such as otitis media, sinusitis, pneumonia, bacteremia and meningitis. Polysaccharide conjugate vaccines (PCV) are based on the induction of antibodies against capsular polysaccharides and they are very efficient against invasive pneumococcal infections. The widespread use of PCVs has also led to an increase in colonization and disease caused by non-vaccine serotypes though. Furthermore, an increase in the isolation of non-encapsulated pneumococci (NESp) has also been reported. An alternative to overcome these shortcomings is the use of protein antigens, which could be also administered in combination with PCVs. This project aims to compare the efficacy of PCV and the protein antigen PspA (Pneumococcal surface protein A) in a model of co-colonization of the mouse nasopharynx. The concomitant colonization with more than one pneumococcal isolate is very common, especially in children. The efficacy of different formulations will be evaluated for the capacity to control the co-colonization with two vaccine serotypes (6B and 23F) and also the co-colonization with one isolate from a vaccine serotype (6B or 23F) and another isolate from a non-vaccine serotype (15C or 33F). Furthermore, the efficacy of the immunization of the protein antigen PsaA (Pneumococcal surface antigen A) will be evaluated in a model of colonization with a NESp isolate. This project thus aims at the evaluation of the efficacy of new vaccine formulations against different pneumococcal isolates, since epidemiological data obtained after the introduction of PCVs show a dynamic scenario, with the alteration of prevalence of serotypes in colonization and invasive disease. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

COLICHIO, GABRIELA B. C.; OLIVEIRA, GIULIANA S.; RODRIGUES, TASSON C.; OLIVEIRA, MARIA LEONOR S.; MIYAJI, ELIANE N.. Efficacy of a Protein Vaccine and a Conjugate Vaccine Against Co-Colonization with Vaccine-Type and Non-Vaccine Type Pneumococci in Mice. PATHOGENS, v. 9, n. 4, APR 2020. (16/09427-5)