Passive Immunization and Vaccination Flashcards
Passive immunization
Transfer of pre-formed immunity (usually Abs) produced in one “individual” into another naive host
Two types:
Natural passive immunization - Ab from other to child through placenta (IgG) or in colostrum/breast mil (IgA)
Artificial passive immunization - transfer of mAb or polyclonal Ab (IVIG)
Clinical uses of passive immunization
- Prevent infectious disease progression after known exposure (i.e. needle stick w/ Hep B)
- Ameliorate sxs of ongoing disease
- Protect immunodeficient Pt’s who have been exposed to pathogen
- Block toxin actions
- Kill tumor cells (most widespread use of passive immunity)
What molecules acts as the strongest immunogens?
Proteins - can be presented by MHC I and II
What disease processes can be vaccinated against after exposure?
Hepatitis B or Rabies
What vaccines induce the”best” most long-lasting immunity?
Attenuated live vaccines
Replicate within host
Some live-attenuated vaccine strains can cause severe disease in immunocompromised patients and are, therefore, contraindicated in the immunosuppressed, infants, and their close contacts.
Another disadvantage of these vaccines is that there is a low possibility that they can regain virulence via reversion mutations (i.e. polio live vaccine)
Inactivated vaccines
Generally require multiple vaccinations to sustain immune response
Tend to induce a primarily humoral response w/ relatively low induction T-cell mediated responses
I.e. Rabies virus, Salk poliovirus and Sinopharm BBIBP SARS-CoV-2 vaccines
Subunit vaccines
Purified pathogen protein or carbohydrate Ags
Elicit protective Ags - composed of a pathogen host cell binding protein that elicits neutralizing Abs
I.e. Hep B and HPV vaccines
Avirulent recombinant viral vector vaccines
Use a non- or less- pathogen virus vector (like adeonvirus or vaccinia virus) that has been genetically modified so that:
- It does not replicate after infection of host cell
- Expresses protein from other pathogens that will induce a protective adaptive immune response to those pathogens
i.e. J&J SARS-CoV-2 and rVSV-ZEBOV Ebola virus vaccines
What types of pathogens are there conjugate vaccines available for?
Streptococcus pneumoniae
Hemophilus influenzae
Neisseria meningitidis
Good for encapsulated bacteria (i.e. those listed above)
Specifically designed to elicit opsonizing IgG to bacterial capsules?
Which vaccine type is specifically designed to elicit opsonizing IgG to bacterial capsules?
Conjugate vaccines (becuase of IgG - carbohydrate subunit vaccines produce IgM)
B. Revaccinating a member of the nursing staff against Hep B after a needle stick
E. Smallpox
Close to eradicating polio
A. Subunit vaccine
