Haemophilus influenzae b capsular polysaccharide with a protein is a(n)

A) Inactivated whole-agent vaccine.
B) Toxoid vaccine.
C) Nucleic acid vaccine.
D) Subunit vaccine.
E) Conjugated vaccine.

E) Conjugated vaccine.

Haemophilus influenzae b (Hib). which is responsible for a form of childhood meningitis, produces an external glycocalyx coat called a capsule. The polysaccharide capsule itself does not elicit an immune response, but the capsule is attached (or conjugated) to a tetanus or diphtheria toxoid. Such an attachment initiates a strong response by the immune system.