Inactivated Vaccines

Inactivated vaccines are usually made by exposing virulent virus to chemical or physical agents like formalin or beta-propiolactone to destroy infectivity while retaining immunogenicity.

The chemical or physical treatment used to eliminate infectivity of inactivated virus vaccines may be damaging enough to modify immunogenicity, particularly of antigens needed to elicit cell-mediated immune responses. The result is an immune response that is shorter in duration, narrower in spectrum for viral antigens, weaker cell-mediated and mucosal immune responses, and probably less effective in preventing viral entry.

Therefore, such vaccines need to use large amounts of antigen to elicit an adequate antibody response– a major disadvantage.