Which one of the following statements is NOT true about polysaccharide vaccines?

a. A unique type of inactivated subunit vaccines composed of long chains of sugar molecules that make up the surface capsule of encapsulated bacteria.
b. The immune response to a pure polysaccharide vaccine is typically T cell independent, which means these vaccines are able to stimulate B cells without the assistance of T-helper cells.
c. T cell-independent antigens are not consistently immunogenic in children < 2 years of age.
d. The antibody made in response to pure polysaccharide antigens is mostly of the IgG class.

Answer: d. The antibody made in response to pure polysaccharide antigens is mostly of the IgG class.