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hib

jamama
http://www.ncbi.nlm.nih.gov/pubmed/8182813

The committee found that the evidence favored acceptance of a causal relation between diphtheria and tetanus toxoids and Guillain-Barré syndrome and brachial neuritis, between measles vaccine and anaphylaxis, between oral polio vaccine and Guillain-Barré syndrome, and between unconjugated Hib vaccine and susceptibility to Hib disease.


Why?
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Re: hib

Science Mom
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Weird isn't it?  The old Hib polysaccharide vaccines caused Hib-specific immunosuppression in children given the vaccine so they became more susceptible to Hib disease.  This effect was experimentally seen with larger doses of vaccine.  There was some kind of inhibition that the vaccine produced causing vaccinees to be more susceptible to Hib disease a short time post-vaccination.

These vaccines are no longer in use as the conjugated vaccines have replaced them and do not produce the same effect.

SM
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Re: hib

jamama
So, at this point, the only way to vaccinate a child for Hib is with a conjugate vaccine and there are no Hib only vaccines available?  
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Re: hib

Science Mom
Administrator
I think you are confusing combination vaccine with conjugate vaccine.  Hib is made as a conjugate (joining of different proteins) but is a Hib only vaccine, except for Pentacel (DTaP-Hib-IPV) or Comvax (Hib-HepB), those are combination vaccines.  Conjugate vaccines are made with parts of other organisms, like diphtheria proteins or tetanus toxoids (a protein) in order to 'trick' the immune system into paying attention to the Hib proteins and making antibodies against them.  Does that make sense?

The Hib only vaccines are: ActHib, HibTiter and Pedvax Hib although I'm not sure if HibTiter is being made any more.

SM
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Re: hib

carrie
yeah I would think you would WANT the conjugate vaccine to be the only one out there because this vaccine is the one that allows a child under 18 months to recognize the hib protein coat and create antibodies. Use any other vaccine from the past and you would leave that child unprotected, right?
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Re: hib

jamama
You're right, conjugate/combination was confusing me.

So now, with ACTHib, for example, does it confer any immunity to tetanus or just hib?
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Re: hib

Science Mom
Administrator
Any immunity produced by the tetanus toxoid would be negligible as there is only enough to provide a vehicle for the Hib polysaccharides.

SM