Primary immunoglobulin secreted or activated after vaccination:

# Primary immunoglobulin secreted or activated after vaccination:

A. IgM

B. IgA

C. IgG

D. IgE

The primary immunoglobulin secreted or activated after vaccination is:

C. IgG

Explanation:

IgG is the most abundant antibody in blood and extracellular fluid, making up ~75% of serum immunoglobulins. It is the key effector of the secondary immune response (activated after initial exposure or vaccination).

IgM is produced first during the primary immune response but is short-lived. Vaccination typically aims to induce long-term immunity via IgG.

IgA is important for mucosal immunity (e.g., respiratory/gut lining) but is not the dominant systemic response to vaccines.

IgE is associated with allergies/parasitic infections and plays no significant role in vaccine-induced immunity.