Sorry this is a tad tl.
That is
the justification for deferring vaccination while febrile illness is present:
You have to be careful interpreting information intended to inform patients or parents. The information is intended to explain simply why we ask about illness but only defer vaccine sometimes. You have to realize we are asking parents to tell us if their kids are ill, then in some cases saying, but don't worry, it doesn't matter.
I don't particularly like they way the author worded the information, but that's just my penchant for getting the science right. The author makes a contradictory statement:
Data on the capacity of vaccines to induce protective immune responses in children with severe infections (such as those with bacterial pneumonia or meningitis) are lacking.
Although a delay in vaccines is recommended for children with severe illnesses until the symptoms of illness resolve, this recommendation is not based on the likelihood that the child will have an inadequate immune response to the vaccine.
So there's no data but that's no reason to draw a conclusion? Maybe that author is comfortable claiming X despite the lack of data to confirm X, I don't make prescribing decisions that way. On the other hand, you can't always tell patients/parents everything in a handout or on an information page.
Your source agrees with what I said.
- In kids with low grade illness we have data backing the conclusion vaccine efficacy is not affected.
- It is prudent to not add potential vaccine reactions to existing symptoms but that isn't an absolute contraindication.
- And with some vaccines, like pertussis, it is important not to mistake an illness symptom for a vaccine reaction.
I stand by my claim that last reason there is still a "
pretty weak argument with perhaps the exception of pertussis vaccine or DPTs".
Thanks but that doesn't address your claim that influenza vaccine efficacy is compromised due to intra-antigenic competition. I've seen reports of influenza N and H antigens competition (vaccine development studies/reports not wild-type) but that isn't really germane.
That wasn't my claim. The standard vaccine contains 3 strains so obviously the immune response to flu antigen is not thought to be interfering with flu antigen in the vaccine.
What I said was, and it is consistent with your citation, there is no data to know if flu vaccine efficacy is affected by severe illness. No data means you don't normally do it, medicine today is evidence based, not lack-of-evidence-against based.
The example I cited was supporting the
theoretical assumption immune responses to one vaccine can be altered in the presence of an ongoing immune response to another pathogen.
[sidetrack] ** You might be interested: Some very complex interactions of the antibody-antigen immune responses have been discovered in recent years, more complex than anyone knew before.
Dengue hemorrhagic fever turns out to be caused when one is infected first by one strain, antibody develops, and that antibody then makes the infection with a second strain fulminate.
Four different dengue viruses are known to cause dengue hemorrhagic fever. Dengue hemorrhagic fever occurs when a person catches a different type dengue virus after being infected by another one sometime before. Prior immunity to a different dengue virus type plays an important role in this severe disease.
This stuff is fascinating, especially because in the past we had no idea such complex interactions were occurring. The link doesn't discuss the interaction but you can find it with a PubMed search if you're interested.[/sidetrack]
