Related Experiment Videos
Protection of infant mice from challenge with Streptococcus pneumoniae type 19F by immunization with a type 19F
C J Lee1, R A Lock, P W Andrew
1Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892.
Insights
This study shows that a new conjugate vaccine against Streptococcus pneumoniae type 19F is effective. Immunizing pregnant mice and their offspring significantly boosted protective antibodies and survival rates against pneumococcal infection.
Area of Science:
- Immunology
- Vaccinology
- Microbiology
Background:
- Streptococcus pneumoniae causes significant infant mortality.
- Pneumococcal vaccines are crucial for preventing invasive disease.
- Developing effective infant vaccines requires understanding immunogenicity and protective efficacy.
Purpose of the Study:
- To investigate the immunogenicity and protective efficacy of a novel conjugate vaccine.
- To evaluate a conjugate of Streptococcus pneumoniae type 19F polysaccharide and pneumolysin toxoid.
- To assess vaccine effectiveness in an infant mouse model.
Main Methods:
- Administered conjugate vaccine to Balb/c mice during gestation, lactation, and to offspring.
- Measured anti-polysaccharide and anti-pneumolysin antibody titers in infant mice.
- Challenged immunized and control infant mice with type 19F pneumococci and assessed bacterial clearance and survival rates.
Main Results:
- Immunization with the conjugate significantly increased anti-polysaccharide and anti-pneumolysin antibody titers in infant mice.
- Significantly enhanced clearance of type 19F pneumococci from the blood of immunized mice.
- Demonstrated a significantly higher survival rate in immunized infant mice compared to controls.
Conclusions:
- The pneumolysin-polysaccharide conjugate vaccine induces protective anti-pneumococcal responses in infant mice.
- Immunization during gestation or early infancy is effective in conferring protection.
- Pneumolysoid-polysaccharide conjugates show promise as components for human pneumococcal vaccines.
Abstract:
The immunogenicity and protective efficacy of a conjugate of Streptococcus pneumoniae type 19F polysaccharide and a genetically toxoided derivative of the pneumococcal toxin pneumolysin was investigated in an infant mouse model. The conjugate was administered to Balb/c mice during pregnancy and/or lactation, and to their offspring during early infancy. The anti-polysaccharide and anti-pneumolysin titres of the immunized infant mice were significantly higher than those of non-immunized controls. When the infant mice were challenged with type 19F pneumococci, the bacteria were cleared more effectively from the blood of immunized mice than from that of control mice. The survival rate for the immunized mice was also significantly higher than that for the control group. These results indicate that highly protective anti-pneumococcal responses can be induced in infant mice by immunization with the conjugate during gestation or early infancy, and suggest a possible role for pneumolysoid-polysaccharide conjugates as human vaccine components.