Efficacy of a protein vaccine and a conjugate vaccine against co-colonization with vaccine-type and non-vaccine type pneumococci in mice
Pathogens
; 9(4): 278, 2020.
Article
in English
| Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP
| ID: but-ib17615
Responsible library:
BR78.1
Localization: BR78.1
ABSTRACT
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
Full text:
Available
Collection:
National databases
/
Brazil
Database:
Sec. Est. Saúde SP
/
SESSP-IBPROD
Language:
English
Journal:
Pathogens
Year:
2020
Document type:
Article