Efficacy of a Protein Vaccine and a Conjugate Vaccine Against Co-Colonization with Vaccine-Type and Non-Vaccine Type Pneumococci in Mice

Autor(es)

Colichio, Gabriela B. C. ^[1] ; Oliveira, Giuliana S. ^[1] ; Rodrigues, Tasson C. ^[1] ; Oliveira, Maria Leonor S. ^[1] ; Miyaji, Eliane N. ^[1]

Afiliação do(s) autor(es)

^[1] Inst Butantan, Lab Bacteriol, BR-05503900 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: PATHOGENS; v. 9, n. 4 APR 2020.
• Citações Web of Science: 0

Resumo

Widespread use of pneumococcal conjugate vaccines (PCVs) has led to substitution of vaccine-type (VT) strains by non-vaccine type (NVT) strains in nasopharyngeal carriage. We compared the efficacy of PCV13 and a nasal protein formulation containing pneumococcal surface protein A (PspA) adjuvanted with the whole-cell pertussis vaccine (wP) in the protection against co-colonization challenge models in mice with VT and NVT strains expressing different PspAs. Immunized mice were challenged with two different mixtures: i. VT4 (PspA3) + NVT33 (PspA1) and ii. VT23F (PspA2) + NVT15B/C (PspA4). Results from the first mixture showed a reduction in loads of VT4 strain in the nasopharynx of mice immunized with PCV13. A statistical difference between the loads of the VT and NVT strains was observed, indicating a competitive advantage for the NVT strain in PCV13-immunized animals. In the second mixture, no reduction was observed for the VT23F strain, probably due to low levels of anti-23F polysaccharide IgG induced by PCV13. Interestingly, a combination of the PspA formulation containing wP with PCV13 led to a reduction in colonization with both strains of the two mixtures tested, similar to the groups immunized nasally with wP or PspA plus wP. These results indicate that a combination of vaccines may be a useful strategy to overcome pneumococcal serotype replacement. (AU)

• Processo FAPESP: 16/09427-5 - Comparação da imunização com a vacina conjugada polissacarídica e com antígenos proteicos no controle da co-colonização por Streptococcus pneumoniae
• Beneficiário: Eliane Namie Miyaji
• Modalidade de apoio: Auxílio à Pesquisa - Regular