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11 Cards in this Set
- Front
- Back
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Why is the IP vaccine used in the US?
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Because of the risk of wild type transformation and slight risk of poliomyelitis.
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Why is the OPV used by WHO in their eradication program?
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It is cheap and doesn’t use needles. Also has communicable protection with all contacts.
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What are the advantages and disadvantages of IP v OPV?
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OPV- sabin- cheaper, local immunity (produces IgA), response rate of 100%, and it allows secondary spread to non immunized contacts. downside is that it is a live attenuated virus and can convert to wild type and cause poliomyelitis
IPV-salk- formalin inactivated virus with no chance of revertion, does not provide local immunity to the gut but prevents viremia |
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At what age is paralytic of most concern? How does this affect our concerns about the polio vaccination program?
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Paralytic polio is most common in teenagers and young adults. If we stop vaccinating because we think we have erradicated polio and there is an outbreak we would have a huge number of nonimmune individuals. The virus is also shed for a long time especially in people with immune problems and the fact that the virus can mutate from the vaccine strain to wild type virus is of concern.
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What are the reasons that vaccines have not been developed for ECHO and Coxsackie virus?
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Multiplicity of serotpyes and there isn’t much interest except against enterovirus and coxsackie B.
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What diseases are caused by coxsackie and ECHO virus?
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Group A coxsackie- diffue myositis, acute inflammation and necrosis of voluntary muscles. Hand foot mouth disease, herpangina, conjunctivitis,
Group B coxsackie- focal areas of degneration in the brain, necrosis in skeletal muscles, inflammatory change in dorsal fat pad, pancreas, and maybe myocardium. Epidemic pleurodynia, myocarditis, neonatal, ECHO virus- paralytic disease, meningitis/encephalitis, carditis, neonatal, rash, resp., undifferentiated fever. |
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Can picornaviruses RNA be directly translated into proteins?
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Yes, they are positive sense RNA viruses
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How do we get revertants from OPV to wild type virus?
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A point mutation at position 472 of sabin OPV3 within the 5 noncoding region and its internal ribosomal entry site is known to be an attenuating sequence for serotype 3, reversion of this nucleotide (wild type) has been associated with VAPP (vaccine associated paralytic poliomyelitis
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What is the main impediment to the development of a rhinovirus vaccine?
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Immunity is type specific, IgA, and is short lived
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Why is rhinovirus replication limited to the upper respiratory tract?
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Rhinoviruses are unstable in acid pH.
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How can rhinovirus infections be prevented?
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Control of sick contacts (?)
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