Question

Which material may be present in vaccines?

Options

• Only full disease under normal conditions

• Only memory B-cells and memory T-cells

• Weakened pathogens, killed pathogens, or their antigenic proteins

• Only specific antibodies against future infection

Answer 1

Vaccines may contain weakened pathogens, killed pathogens, or their antigenic proteins. These materials trigger antibody formation without causing full disease under normal conditions.