Can We Discuss DTaP and Transmission? - Page 2

[quarteralien]

So, in English, what are FHA and pertractin?

[kriket]

Originally Posted by quarteralien

So, in English, what are FHA and pertractin?

they are pieces of Pertussis.
Pertractin is the "house" or outer membrane protein that sticks to epithelial cells. FHA is the tendril that grabs on. "it is a fimbrial-like structure on the bacterial surface, and cell-bound pertussis toxin (PTx). Short range effects of soluble toxins play a role as well in invasion during the colonization stage."

http://www.textbookofbacteriology.net/pertussis.html for FHA Pertractin, just google for a refrence

[2boyzmama]

Originally Posted by quarteralien

So, in English, what are FHA and pertractin?

Originally Posted by kriket

they are pieces of Pertussis.
Pertractin is the "house" or outer membrane protein that sticks to epithelial cells. FHA is the tendril that grabs on. "it is a fimbrial-like structure on the bacterial surface, and cell-bound pertussis toxin (PTx). Short range effects of soluble toxins play a role as well in invasion during the colonization stage."

http://www.textbookofbacteriology.net/pertussis.html for FHA Pertractin, just google for a refrence

See, this is the exact problem with this!!! Part of it IS the toxin, however do you notice how they use the word "toxoid" for D and T, but "toxin" for a portion of P? Why? And the other two portions are the acellular part of the pertussis bacteria, as I understand it. So the *idea* is that the vaccine is created to protect against the toxoid AND the bacteria, but because there were such severe effects from the old whole-cell vaccine, they switched to acellular and it isn't as effective.

It's all mumbo jumbo, and drives me crazy!!! With my son's particular special needs, I really *want* to give him protection from pertussis, even just partial protection, but not until I understand this vaccine more!!!

It is clear, though, that the argument of "it doesn't prevent transmission because it protects against the toxin" isn't quite accurate or complete. Does someone want to call the CDC vaccine information line and ask this question??? I might do it, actually.

[quarteralien]

In my rereading of the pertussis chapter of the Pink Book, I found a passage that said the acellular version was more effective than the old whole cell version. : But everywhere you hear about it, you hear that it's safer, but less effective. I don't think anyone has the straight scoop on this vax.

[Proverbs31]

^^Reminds me of Dr. Mendelsohn's saying: you only hear about the downsides of a drug when a replacement drug is introduced...

[tanyalynn]

Originally Posted by 2boyzmama

Does someone want to call the CDC vaccine information line and ask this question??? I might do it, actually.

Wow, I didn't realize there was a number you could call to ask technical questions.

If you call, can you share the results with us? Pretty please?

[MissRubyandKen]

I've been trying to find the paper I read that stated this but haven't yet. I remember reading that anything short of universal vaccination with DTaP and Tdap wouldn't see a reduction overall in cases of pertussis at this point.

[mamakay]

They do put actual bacterial antigens in there, but they just don't seem to do what they're supposed to do.

Look through some of these...

http://scholar.google.com/scholar?q=...r=&btnG=Search


Especially this one (this is something to send to that infectious disease doc)

http://iai.asm.org/cgi/content/abstract/68/12/7175

Characterization of Bactericidal Immune Responses following Vaccination with Acellular Pertussis Vaccines in Adults

Similarly, opsonization with the postimmunization sera failed to enhance attachment or phagocytosis of bacteria by neutrophils, and one postimmunization sample with a strong response to filamentous hemagglutinin caused an inhibition of phagocytosis that was statistically significant compared to that observed for the no-serum control. In summary, booster immunization of adults with acellular pertussis vaccines was not found to increase bactericidal activity over preimmunization levels. Identifying ways to promote bactericidal immune responses might improve the efficacy of acellular pertussis vaccines.

What they're saying is that the antigens in the vax that are supposed to teach your immune system how to combat the actual bacteria, don't. It should, and it's supposed to....but it doesn't work.

Which is almost certainly why the 5 component acellular vaccine isn't much more effective than the monocomponent "pertussis toxoid only" vaccine.

The antigen they need to have in there is probably this one:

http://iai.asm.org/cgi/content/abstract/68/12/7152

Neutralizing Antibodies to Adenylate Cyclase Toxin Promote Phagocytosis of Bordetella pertussis by Human Neutrophils

But the current pertussis vaccine doesn't have that toxin in there.
Adenylate Cyclase Toxin is sort of like a "forcefield" for the pertussis bacteria.Pertussis excretes that toxin to hide from your immune system. That's probably why the pertussis vax doesn't work to help you clear pertussis more quickly.

[mamakay]

Originally Posted by Shelsi

I think most of us can agree here that the pertussis vax does not prevent transmission.

However doesn't it prevent some transmission? If you have pertussis but no symptoms you're much less likely to spread germs. You're not coughing all over the place, nose running, etc.

Pertussis is most contagious in the first couple of weeks, when you think you just have a cold.
There's no evidence that the vaccine does anything at all to prevent that phase. All we know is that it shortens "the cough"...but by the time you have "the pertussis cough"...you're basically mostly done with the contagious phase.

[mamakay]

http://www.mothering.com/discussions...d.php?t=555012

[mamakay]

And then, back to that ACT toxin that's not in the vaccine...
This is bad:

http://www.journals.uchicago.edu/doi...10.1086/381204

Of particular interest is the lack of a significant ACT antibody response in children for whom the DTP or DTaP vaccines failed. This induced tolerance is intriguing and may be due to the phenomenon called “original antigenic sin” [22]. In this phenomenon, a child responds at initial exposure to all presented epitopes of the infecting agent or vaccine. With repeated exposure when older, the child responds preferentially to those epitopes shared with the original infecting agent or vaccine and can be expected to have responses to new epitopes of the infecting agent that are less marked than normal. Because both vaccines contained multiple antigens (i.e., PT, FHA, PRN, and fimbriae), the patients who had been vaccinated responded to the antigens that they had been primed with and did not respond to the new antigen (i.e., ACT) associated with infection.

That means that, in theory, DTaP vaccinated kids might be MORE CONTAGIOUS when they catch pertussis compared to unvaxed kids after they catch pertussis.

[wallacesmum]

MK, does this

one postimmunization sample with a strong response to filamentous hemagglutinin caused an inhibition of phagocytosis that was statistically significant compared to that observed for the no-serum control

mean that the vaccine caused a statistically significant immune supressant response in one study group?

[mamakay]

Originally Posted by wallacesmum

MK, does this


mean that the vaccine caused a statistically significant immune supressant response in one study group?

In one sample (one person's blood), yes.
His blood was better at "killing" pertussis before being vaccinated.

[mamakay]

I have a pretty thorough understanding of this issue, so if anyone has any questions, feel free to ask.

It is an extremely complex issue, but I don't mind explaining what's known.
We can make a "be all end all" thread for the archives, if any of you want.

[wallacesmum]

All right, so then, what do you think it might mean that the vaccination can actually have a negative effect on resistance?

[mamakay]

Originally Posted by wallacesmum

All right, so then, what do you think it might mean that the vaccination can actually have a negative effect on resistance?

It means the "Do it for your baby!" ads are a scandalous load of hooey, for one...

[tanyalynn]

So what do we know about what the 2mo, 4mo, 6mo, etc series does for/to infants? Is the anti-toxin part that's supposed to make the really heavy coughing actually helping to some extent?

And are there any benefits to teen/adult vaccination? It seems like it's a rare adult who gets the really heavy, debilitating cough. Not impossible, but most cases seem like normal coughs (no one thinks whooping cough, I mean).

What's the most interesting thing you've learned? I have to ask this--I don't know enough to ask the question that would naturally lead here, so I'll just jump to the end-point.

[MissRubyandKen]

mamakay- do you believe that the antigens other than the PT are completely ineffective?

[CookAMH]

Originally Posted by 2boyzmama

PLUS, immunity is wearing off, most adults no long have immunity, and adults tend not to have the classic "whoop", so they are ill with pertussis without knowing it and spreading it around.

It's a very frustrating vaccine...

That is an interesting point. I wonder how much WC starts with adults....

Also, in being a bacteria...lifetime immunity would not necessarily come with natural infection, correct?

[mamakay]

Originally Posted by TanyaLopez

So what do we know about what the 2mo, 4mo, 6mo, etc series does for/to infants? Is the anti-toxin part that's supposed to make the really heavy coughing actually helping to some extent?

And are there any benefits to teen/adult vaccination? It seems like it's a rare adult who gets the really heavy, debilitating cough. Not impossible, but most cases seem like normal coughs (no one thinks whooping cough, I mean).

What's the most interesting thing you've learned? I have to ask this--I don't know enough to ask the question that would naturally lead here, so I'll just jump to the end-point.

Yeah, I think it's the "pertussis toxin" part that helps infants/kids/adults not have such a bad cough.
For adults and teens...older people can get a bad case, too. Not "deadly" and it won't put you in the hospital, but it can be miserable. Really miserable. So I think it would be reasonable to get the shot to spare yourself that misery.

The most interesting thing I've learned is that the people in charge of this stuff are sort of faking it when they act like they really know what's going on.