Attenuated Vaccines Overview

Study Notes

Induce a robust and lasting immune response, providing quick immunity.
Generally contraindicated for individuals with severe immunodeficiencies (e.g., HIV, chemotherapy patients).
Function by prompting the production of antibodies and memory cells against specific pathogens.
Common examples include measles, mumps, rubella, yellow fever, and certain influenza vaccines.
Activate both cellular and humoral immune responses of the adaptive immune system.

Safe and effective with long-lasting immunity; severe adverse reactions are rare among WHO-recommended vaccines.
Very low risk of viruses reverting to pathogenic forms.
Immunocompromised individuals typically unable to develop a safe immune response to live-attenuated vaccines.
Household contacts of immunodeficient individuals can safely receive most attenuated vaccines.
Live-attenuated vaccines not recommended during pregnancy due to risks to the fetus, specifically varicella and yellow fever vaccines.

Created by killing pathogens using heat, chemicals, or radiation; inactivation methods include formaldehyde and beta-Propiolactone.
Split virus vaccines use detergents to disrupt viral envelopes, commonly used in many influenza vaccines.
More stable than live vaccines, facilitating easier storage and transport.
Cannot revert to virulent forms, making them safer for immunocompromised individuals.

Composed of purified parts of viral pathogens, specifically antigenic parts necessary for immune response.
Generated from disassembled viral particles or through recombinant technology using other organisms to produce vaccine antigens.
Safer and more stable due to lack of live components, reducing the risk of disease introduction.
Effective in provoking strong antibody and cell-mediated reactions.
Require only one or two doses, providing quick immunity onset and cost-effectiveness.
Disadvantages include complex manufacturing and potential natural mutations during replication.

Inactivated vaccines suitable for individuals who cannot receive live attenuated versions (e.g., elderly, immunocompromised).
Proper inactivation is crucial; any failure in the process can result in dangerous infectious particles remaining in the vaccine.
Examples of inactivated vaccines include those for influenza, polio (IPV), rabies, and hepatitis A.