To understand the modulation of immune response to polysaccharide (PS) immunogens and attempt to develop a more effective vaccine for prevention of pneumococcal diseases in young children, we studied the immune response of young mice to a type 9V PS-tetanus toxoid (TT) conjugate and the effect of maternal immunization on the immune response of young mice to 9VPS-TT. Young mice at 2 weeks of age produced IgM antibody to 9VPS or PS-protein conjugate. However, only 9VPS-TT conjugate induced an IgG antibody response and an anamestic effect when a second dose of the immunogen was injected at 2 weeks interval. Aluminum hydroxide gel enhanced the IgG antibody response to 9VPS-TT but did not augment the response to 9VPS. The gel also helped in the isotype switching from IgM to IgG. Maternal immunization before and/or during gestation primed young mice to respond effectively to 9VPS-TT conjugate immunogen. Injection of pregnant mice with the conjugate immunogen enhanced the IgG antibody response to 9VPS-TT in the offspring. These results indicated that immunization of mothers with an optimum dose of 9VPS-TT immunogen before and/or during pregnancy and in young children with a PS-protein conjugate can provide young children with an enhanced antibody response to pneumococcal PSs.

Agency
National Institute of Health (NIH)
Institute
Food and Drug Administration (FDA)
Type
Intramural Research (Z01)
Project #
1Z01BA002018-02
Application #
3804603
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
2
Fiscal Year
1991
Total Cost
Indirect Cost