Immunization Flashcards
What is immunization?
Artificially-acquired immunity (active-receives antigen or passive-receive antibodies).
What was the historical method of variolation?
Grinding smallpox scabs from kids with mild cases to infect children.
Who is credited with the first vaccination and what virus did he use?
Edward Jenner used the cowpox (vaccinia) virus to protect against smallpox.
What significant vaccines did Louis Pasteur develop?
Vaccines for fowl cholera, rabies, and anthrax.
What major global health achievements were accomplished by the end of the 20th century through vaccination?
Eradication of smallpox and significant reductions in polio, measles, mumps, rubella, chicken pox, hepatitis A and B.
How many lives do vaccines save annually according to WHO estimates?
2-3 million lives.
What is herd immunity?
Population-level immunity that indirectly protects non-immune individuals.
What are some barriers to immunization?
- Fear due to small risks * Socioeconomic/political issues * Difficulty accessing certain populations * High vaccine development costs.
What are attenuated vaccines?
Live, attenuated organisms or viruses that can infect but not cause disease.
What are the benefits of attenuated vaccines?
- Strong immune response * Contributes to herd immunity.
What are the disadvantages of attenuated vaccines?
- Risk of disease in immunosuppressed individuals * Can cross placenta * Rare reversion to virulent form.
What are killed (inactivated) vaccines?
Whole agent vaccines (whole, killed microbe) or subunit vaccines (antigenic fragments of a microbe).
What is a significant disadvantage of killed vaccines?
No herd immunity (not infectious).
What are toxoid vaccines?
Modified toxins of an organism important for a few bacterial diseases.
What is the definition of passive immunization?
Injection of antibodies to a particular antigen into the blood.
What is a disadvantage of passive immunization?
No memory cell activation (no long-term immunity).
Fill in the blank: The _______ Initiative, launched in 1988, aims at global polio eradication.
Global Polio Eradication
True or False: Attenuated vaccines can replicate and potentially cause disease.
False
What is required for herd immunity?
High immunization rates OR infection with highly contagious strains.
What percentage of childhood deaths can be prevented by vaccination?
25%
What are the risks associated with high vaccine development costs?
Difficulty in accessing certain populations and resistance by organisms.
What type of immune response do exogenous antigens stimulate in killed vaccines?
Th2 response that promotes antibody-mediated immunity.
