[RachelGS]

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<table border="0" cellpadding="6" cellspacing="0" width="99%"><tr><td class="alt2" style="border:1px inset;">Specific recommendations for the use of varicella vaccines are as follows:<br><br>
* For children aged 12 months or older, adolescents, and adults without evidence of immunity, two 0.5-mL doses of varicella vaccine should be given subcutaneously. The recommended minimum interval between the 2 doses is 3 months for children aged 12 months to 12 years. However, if the second dose was given more than 28 days after the first dose, the second dose does not have to be repeated. For persons aged 13 years and older, 4 weeks is the recommended minimum interval.<br><br>
* Single-antigen varicella vaccine is approved for use in healthy persons aged 12 months or older, whereas combination MMRV vaccine for simultaneous vaccination against MMRV is approved for use in healthy children aged 12 months to 12 years. Whenever any components of the combination vaccine are indicated and the other components are not contraindicated, the MMRV vaccine or other licensed combination vaccines is preferred over separate injection of equivalent component vaccines.<br><br>
* Routine vaccination schedules for young children are as follows: all healthy children should receive their first dose of varicella-containing vaccine at age 12 to 15 months. A second dose of varicella vaccine is recommended for all children aged 4 to 6 years before entering school, but it may be given earlier as long as the interval between the first and second dose is more than 3 months. Because of the risk for VZV transmission in schools, all children entering school should have received 2 doses of varicella-containing vaccine or have other evidence of immunity to varicella.<br><br>
* Routine vaccination schedules for adolescents and students are as follows: persons aged 13 years or older without evidence of varicella immunity should be given two 0.5-mL doses of single-antigen varicella vaccine subcutaneously, 4 to 8 weeks apart. If more than 8 weeks elapse after the first dose, the second dose may be given without restarting the schedule. The MMRV vaccine is not licensed for use in anyone aged 13 years or older. All students should be evaluated for varicella immunity, and those without such evidence should routinely receive 2 doses of single-antigen varicella vaccine 4 to 8 weeks apart.<br><br>
* All healthy adults should be evaluated for varicella immunity, and those without such evidence should be given 2 doses of single-antigen varicella vaccine 4 to 8 weeks apart. Special consideration for vaccination should be given to adults without evidence of immunity who might be at increased risk for exposure or transmission.<br><br>
* Second-dose, catch-up varicella vaccination is recommended for children, adolescents, and adults previously given 1 dose to improve individual protection against varicella and to more rapidly control school outbreaks. Catch-up vaccination may be given during routine healthcare provider visits, such as the recommended health maintenance visit at age 11 to 12 years, and through school and college entry requirements. Although the recommended minimum interval between the first dose and the catch-up second dose is 3 months for children aged 12 years or younger and 4 weeks for persons aged 13 years or older, the catch-up second dose may be given at any interval longer than the minimum recommended interval.<br><br>
* Pregnant women should undergo prenatal evaluation for evidence of varicella immunity. Because of the potentially devastating sequelae of varicella infection during pregnancy, birth before 1980 is not considered evidence of immunity for pregnant women. After delivery or pregnancy termination, women without evidence of varicella immunity should be given the first dose of vaccine before hospital discharge and the second dose 4 to 8 weeks later at the postpartum visit.</td>
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<a href="http://www.medscape.com/viewarticle/558838?src=mp" target="_blank">http://www.medscape.com/viewarticle/558838?src=mp</a><br><br><img alt="" class="inlineimg" src="http://www.mothering.com/discussions/images/smilies/banghead.gif" style="border:0px solid;" title="banghead">

 

[Spirit Dancer]

Man, I honestly wonder how many vaccines they will give before parents decide that it is enough. How many "routine " vaccines will be give 5 even 2 years from now?

 

[RachelGS]

I find this one so scary, though. Especially scary, because chicken pox in adulthood is so brutal and dangerous, and the vaccine is removing the chance for natural (lasting) immunity. It's a problem.

 

[Electra375]

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<div>Originally Posted by <strong>RachelGS</strong> <a href="/community/forum/post/8548213"><img alt="View Post" class="inlineimg" src="/community/img/forum/go_quote.gif" style="border:0px solid;"></a></div>
<div style="font-style:italic;">I find this one so scary, though. Especially scary, because chicken pox in adulthood is so brutal and dangerous, and the vaccine is removing the chance for natural (lasting) immunity. It's a problem.</div>
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TA. Pertusis is equally unnerving. Pertusis in early childhood is not usually dangerous and having pertusis give someone life long immunity, it also makes breastfed baby much less likely to contract pertusis and we all know it is dangerous in those under 6 mo old. So now that adults no longer have immunity due to the lovely vaccine, adults are giving pertusis to infants b/c their mom's are not immune or breastfeeding and the vaccine isn't effective until at least 3 doses are given. SO, now vax adults against a childhood illness!<img alt="" class="inlineimg" src="/img/vbsmilies/smilies/dizzy.gif" style="border:0px solid;" title="Dizzy">:<br><br>
And my dh was conned into it<img alt="" class="inlineimg" src="http://www.mothering.com/discussions/images/smilies/irked.gif" style="border:0px solid;" title="irked">: I'm still loathing about him getting a tetanus shot at his doc appt, I didn't know I had to go with him and tell him to just say no.<br><br>
So, lets see CP will no longer be in children, it is very bad for adults and there is no longer immunity and guess who will be next to be afflicted and challenged baby infants, especially if wild CP is no longer around. But it will come back, the disease cycles over history seem to come back.<br><br>
ETA - so glad I homebirth... I had titers taken in 96, but you know they feel the need to retake those all the time...

 

[Science Mom]

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<div>Originally Posted by <strong>Electra375</strong> <a href="/community/forum/post/8548247"><img alt="View Post" class="inlineimg" src="/community/img/forum/go_quote.gif" style="border:0px solid;"></a></div>
<div style="font-style:italic;">TA. Pertusis is equally unnerving. Pertusis in early childhood is not usually dangerous and having pertusis give someone life long immunity, it also makes breastfed baby much less likely to contract pertusis and we all know it is dangerous in those under 6 mo old. So now that adults no longer have immunity due to the lovely vaccine, adults are giving pertusis to infants b/c their mom's are not immune or breastfeeding and the vaccine isn't effective until at least 3 doses are given. SO, now vax adults against a childhood illness!<img alt="" class="inlineimg" src="/img/vbsmilies/smilies/dizzy.gif" style="border:0px solid;" title="Dizzy">:</div>
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Electra, Pertussis epidemiology doesn't work this way. Pertussis in early childhood is when it is the most dangerous. Pertussis infection does not confer lifelong immunity. The vaccine has nothing to do with adults acquiring pertussis, it is not an epidemiological shift phenomenon. It is that there are numerous circulating <i>Bordatella spp.</i> and the vaccine efficacy is very short lived so it actually makes more sense for the adult population to maintain high vaccine uptake which will do much more to confer protection for susceptible infants than just vaccinating the infant population.<br><div style="margin:20px;margin-top:5px;">
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<table border="0" cellpadding="6" cellspacing="0" width="99%"><tr><td class="alt2" style="border:1px inset;">So, lets see CP will no longer be in children, it is very bad for adults and there is no longer immunity and guess who will be next to be afflicted and challenged baby infants, especially if wild CP is no longer around. But it will come back, the disease cycles over history seem to come back.</td>
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If wild-type chicken pox is no longer circulating then how does that pose a problem with infants? Could you clarify how disease cycles over history seem to come back?<br><br>
SM

 

[Electra375]

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<div>Originally Posted by <strong>Science Mom</strong> <a href="/community/forum/post/8548307"><img alt="View Post" class="inlineimg" src="/community/img/forum/go_quote.gif" style="border:0px solid;"></a></div>
<div style="font-style:italic;">Pertussis infection does not confer lifelong immunity.<br>
SM</div>
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So, since I had pertusis, I'm not immune? Or am I able to better fight it off since I've actually had it. Have I had it wrong all these years? I mean, I always thought since I had pertusis, that my bf children while bfing were not likely to aquire pertusis if it came around or if they did it would be less severe. I don't think anyone could change my mind on this, if they tried.<br><br>
I do not personally believe in complete irradication of diseases. Under that assumption wild chicken pox will never completely leave society. Viruses mutate to survive, basic biology. I see CP as looking like it is laying dormant when really it is adapting to change and will immerge on the scene either stronger or something different from the same virus gene strain. As it is CP vaccine does not protect against Shingles, shingles is worse than CP. And I know way too many vaccinated children who get CP to think it is just a crappy vaccine, it is possible it is a gene mutation of the original virus.<br><br>
Shingles in a baby would be horrifying, worse than CP.

 

[Science Mom]

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<div>Originally Posted by <strong>Electra375</strong> <a href="/community/forum/post/8548448"><img alt="View Post" class="inlineimg" src="/community/img/forum/go_quote.gif" style="border:0px solid;"></a></div>
<div style="font-style:italic;">So, since I had pertusis, I'm not immune? Or am I able to better fight it off since I've actually had it. Have I had it wrong all these years? I mean, I always thought since I had pertusis, that my bf children while bfing were not likely to aquire pertusis if it came around or if they did it would be less severe. I don't think anyone could change my mind on this, if they tried.</div>
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Naturally acquired immunity lasts anywhere from 4-20 years although 7-10 years is more realistic; the extreme range is due to survey differences. If you acquire another pertussis infection while you still have immunity then yes, the infection would be lowly symptomatic and the infection would have a boosting effect. No offense but I am not interested in changing anyone's mind, I just like to see accurate information disseminated.<br><br><div style="margin:20px;margin-top:5px;">
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<table border="0" cellpadding="6" cellspacing="0" width="99%"><tr><td class="alt2" style="border:1px inset;">I do not personally believe in complete irradication of diseases.</td>
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Well, what about smallpox?<br><div style="margin:20px;margin-top:5px;">
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<table border="0" cellpadding="6" cellspacing="0" width="99%"><tr><td class="alt2" style="border:1px inset;">Under that assumption wild chicken pox will never completely leave society. Viruses mutate to survive, basic biology. I see CP as looking like it is laying dormant when really it is adapting to change and will immerge on the scene either stronger or something different from the same virus gene strain.</td>
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Actually, there are already numerous genotypes circulating with a primarily geographic foci with highly conserved genomes that have remained antigenically stable, just have other viruses that we vaccinate against (note: stable does not equal static, mutational rates are extremely low).
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<table border="0" cellpadding="6" cellspacing="0" width="99%"><tr><td class="alt2" style="border:1px inset;">As it is CP vaccine does not protect against Shingles, shingles is worse than CP.</td>
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Actually there is a varicella vaccine that does protect for shingles (Zostavax) and for the record, repeated exposure to wild-type varicella is required for sustained immunity.<br><div style="margin:20px;margin-top:5px;">
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<table border="0" cellpadding="6" cellspacing="0" width="99%"><tr><td class="alt2" style="border:1px inset;">And I know way too many vaccinated children who get CP to think it is just a crappy vaccine, it is possible it is a gene mutation of the original virus.</td>
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I am not quite sure what you are trying to say so I will address what you may mean; first, the vaccine is an attenuated strain of the Oka varicella strain so of course it is mutated. Or second, break-through varicella infection in vaccinated children are not mutations of the circulating strains in the U.S., they are just that, breakthrough infections with strains that are already there.<br><br>
SM

 

[junomama]

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<div>Originally Posted by <strong>Science Mom</strong> <a href="/community/forum/post/8549583"><img alt="View Post" class="inlineimg" src="/community/img/forum/go_quote.gif" style="border:0px solid;"></a></div>
<div style="font-style:italic;">Actually, there are already numerous genotypes circulating with a primarily geographic foci with highly conserved genomes that have remained antigenically stable, just have other viruses that we vaccinate against (note: stable does not equal static, mutational rates are extremely low).</div>
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SM, in trying to follow this conversation, I found myself stumped here. Could you please paraphrase this in easier-to-understand language? <img alt="" class="inlineimg" src="http://www.mothering.com/discussions/images/smilies/redface.gif" style="border:0px solid;" title="Embarrassment">

 

[Science Mom]

Junomama, Sorry about that and thanks for asking for a clarification, I am most happy to do so. There are numerous strains of varicella (chickenpox) with substrains. These are differentiated based upon their DNA sequences. The strains tend to circulate in different regions of the world. The genomes of the strains are highly conserved meaning that there is very little difference between them and they don't mutate at high rates unlike influenza strains. Measles and mumps viruses for example also have numerous strain differences but are also very stable. I hope this helps.<br><br>
SM

 

[arlecchina]

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<div>Originally Posted by <strong>Science Mom</strong> <a href="/community/forum/post/8551580"><img alt="View Post" class="inlineimg" src="/community/img/forum/go_quote.gif" style="border:0px solid;"></a></div>
<div style="font-style:italic;">Junomama, Sorry about that and thanks for asking for a clarification, I am most happy to do so. There are numerous strains of varicella (chickenpox) with substrains. These are differentiated based upon their DNA sequences. The strains tend to circulate in different regions of the world. The genomes of the strains are highly conserved meaning that there is very little difference between them and they don't mutate at high rates unlike influenza strains. Measles and mumps viruses for example also have numerous strain differences but are also very stable. I hope this helps.<br><br>
SM</div>
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I love when you post <img alt="" class="inlineimg" src="http://www.mothering.com/discussions/images/smilies/lol.gif" style="border:0px solid;" title="lol"><br><br>
(dont take that snarky, I mean it...I am home with kids all day and I need big words! <img alt="" class="inlineimg" src="http://www.mothering.com/discussions/images/smilies/lol.gif" style="border:0px solid;" title="lol">)

 

[mamakay]

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<div>Originally Posted by <strong>SM</strong></div>
<div style="font-style:italic;">It is that there are numerous circulating Bordatella spp. and the vaccine efficacy is very short lived so it actually makes more sense for the adult population to maintain high vaccine uptake which will do much more to confer protection for susceptible infants than just vaccinating the infant population.</div>
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I'm just not seeing how one shot every ten years is going to be more than a drop in the bucket compared to this:<br><br><a href="http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=ShowDetailView&TermToSearch=8527557&ordinalpos=40&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum" target="_blank">http://www.ncbi.nlm.nih.gov/sites/en...ubmed_RVDocSum</a><br><br><div style="margin:20px;margin-top:5px;">
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<table border="0" cellpadding="6" cellspacing="0" width="99%"><tr><td class="alt2" style="border:1px inset;"><b>To investigate the frequency of unrecognized Bordetella pertussis infections in adults, we performed IgA and IgG ELISA antibody studies with four B. pertussis antigens</b>--i.e., lymphocytosis-promoting factor, filamentous hemagglutinin, pertactin, and fimbriae-2--in 51 health care workers from whom six consecutive yearly serum samples (from 1984 to 1989) were available. Overall, <b>90% of the subjects had a significant increase in antibody (IgA or IgG) to one or more antigens between 2 consecutive years during the 5-year study period; 55% of subjects had evidence of two infections, 17% had three infections, and 4% had four infections.</b></td>
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That's every couple of years basically that we all catch pertussis subclinically. How in god's name is the vaccine going to do anything better than what we've already got going on?<br>
Unless they make a whole new vaccine that works a whole heck of a lot better than the one we have now, <i>or</i> "natural immunity" when it comes to preventing transmission, I'm not seeing high vax coverage in adults doing doodely squat.

 

[Deborah]

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<table border="0" cellpadding="6" cellspacing="0" width="99%"><tr><td class="alt2" style="border:1px inset;">Unless they make a whole new vaccine that works a whole heck of a lot better than the one we have now, or "natural immunity" when it comes to preventing transmission, I'm not seeing high vax coverage in adults doing doodely squat.</td>
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Well, since the adult version of the vax probably still has thimerosal and aluminum and whatever other goodies they include, it might do a little damage to the overall health of the target population.

 

[Electra375]

Let's remember Pharmaceutical companies are a business, they are for profit businesses. Their economic goal is to make money. Therefore, a sick population which requires more and more treatments keeps them financially sound. And no business is truly ethically moral IMO (I worked enough numbers at an accounting office to know most businesses are playing in the grey area and it irked me).<br><br>
And look at who developed insurance companies - doctors, so that they could get paid.<br><br>
The only doctors I know who are wealthy are dentist, but I'm sure that might just be b/c I'm in a small town. The dentist's 3 daughters each have their own Audi<img alt="" class="inlineimg" src="/img/vbsmilies/smilies/dizzy.gif" style="border:0px solid;" title="Dizzy">:<br><br>
My family doctor drives a minivan... And does not have his own personal gym in his home (the dentist does).

 

[13Sandals]

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<table border="0" cellpadding="6" cellspacing="0" width="99%"><tr><td class="alt2" style="border:1px inset;">Naturally acquired immunity lasts anywhere from 4-20 years although 7-10 years is more realistic; the extreme range is due to survey differences. If you acquire another pertussis infection while you still have immunity then yes, the infection would be lowly symptomatic and the infection would have a boosting effect. No offense but I am not interested in changing anyone's mind, I just like to see accurate information disseminated.</td>
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<br>
I thought the pertussis vaccine only protected against the toxic side effects of the bacteria produced by having the illness - but doesn't do anything to keep transmission down of the actual virus that causes the illness. can someone clarify which it is?

 

[mamakay]

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<div>Originally Posted by <strong>13Sandals</strong> <a href="/community/forum/post/8556847"><img alt="View Post" class="inlineimg" src="/community/img/forum/go_quote.gif" style="border:0px solid;"></a></div>
<div style="font-style:italic;">I thought the pertussis vaccine only protected against the toxic side effects of the bacteria produced by having the illness - but doesn't do anything to keep transmission down of the actual virus that causes the illness. can someone clarify which it is?</div>
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No one really knows totally for sure what's going on with all that. We know the vaccine immunity is not bactericidal. Meaning, it doesn't help your immune system actually kill off pertussis bacteria. All the vaccine helps you do is kill the toxins the bacteria excrete.<br>
Reducing the toxins might help you be <i>slightly less</i> contagious, though, since bacteria use their toxins to "push out" surrounding bacteria when they're trying to set up camp in your body. (there are microscopic wars going on in your body all the time between different types of bacteria, and bacterial toxins are like chemical warfare tools they use.)<br><br>
That effect, if it's there at all, can't be that big, though. Vaccinated kids pass pertussis around all the time. Vaccine immunity also wanes freakishly fast with pertussis, too, so even if that effect is there for a couple of months, it might be more or less gone within a year for all we know.<br>
But really, no one knows what the deal really is. It's only been in the past couple of years that everyone has really come to terms with the fact that the pertussis vaccine isn't everything it was cracked up to be.

 

[Science Mom]

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<div>Originally Posted by <strong>mamakay</strong> <a href="/community/forum/post/8557007"><img alt="View Post" class="inlineimg" src="/community/img/forum/go_quote.gif" style="border:0px solid;"></a></div>
<div style="font-style:italic;">No one really knows totally for sure what's going on with all that. We know the vaccine immunity is not bactericidal. Meaning, it doesn't help your immune system actually kill off pertussis bacteria. All the vaccine helps you do is kill the toxins the bacteria excrete.</div>
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First, to 13Sandals, the <i>Bordatella</i> genus is comprised of bacteria, not virus. MK, there is actually a lot of research going on now and in the past few years with regards to the shifting epidemiology and evolutionary changes in <i>Bordatella spp.</i>. The current vaccines contain antigenic components for 3 pertussis antigens, not just the pertussis toxin; Filamentous hemagglutinin which protects against filamentous hemagglutinin adhesion, a virulence factor that allows bacterial colonsiation of respiratory tract; Pertactin, another virulence factor that functions as an autotransporter for B. pertussis adherence to lung epithelium and pertussis toxin (see below), there is also fimbriae protein in some vaccines but I won't get into that right now.<br><div style="margin:20px;margin-top:5px;">
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<table border="0" cellpadding="6" cellspacing="0" width="99%"><tr><td class="alt2" style="border:1px inset;">Reducing the toxins might help you be <i>slightly less</i> contagious, though, since bacteria use their toxins to "push out" surrounding bacteria when they're trying to set up camp in your body. (there are microscopic wars going on in your body all the time between different types of bacteria, and bacterial toxins are like chemical warfare tools they use.)</td>
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The pertussis toxin actually functions as another virulence factor that facilitates endocytosis, delays neutrophil recruitment to the site of infection and inhibits macrophagic activities. So even if pertussis toxin were the only antigen in the vaccine, if colonisation is inhibited, you are not going to get clinical infection, add to that the other antigens and the bacteria are effectively eliminated by host cell defenses. Why carriage does occur is the lapse in time for this to occur and polymorphisms of antigenic regions of circulating strains are being observed that allow for host cell immune response evasion (also allowing for breakthrough disease). So while carriage may be present, without full-blown disease, the transmission is greatly reduced, how much is intangible.<br><div style="margin:20px;margin-top:5px;">
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<table border="0" cellpadding="6" cellspacing="0" width="99%"><tr><td class="alt2" style="border:1px inset;">That effect, if it's there at all, can't be that big, though. Vaccinated kids pass pertussis around all the time. Vaccine immunity also wanes freakishly fast with pertussis, too, so even if that effect is there for a couple of months, it might be more or less gone within a year for all we know.<br>
But really, no one knows what the deal really is. It's only been in the past couple of years that everyone has really come to terms with the fact that the pertussis vaccine isn't everything it was cracked up to be.</td>
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Children are gross, there is a good reason why transmission occurs amongst them but if you have transmission from one immune child to another immune child, disease would most likely remain sub-clinical. Anti-pertussis antibodies wane quickly but cell-mediated immunity remains, this is also the case for natural infection. The pertussis vaccine was more effective but does need to be re-formulated to address the evolutionary changes that have occurred.<br><br>
SM

 

[A&A]

They have a MMRV now???? <img alt="" class="inlineimg" src="http://www.mothering.com/discussions/images/smilies/headscratch.gif" style="border:0px solid;" title="headscratch"> Great. Just great. Make it EVEN HARDER to differentiate where a reaction is coming from.

 

[mamakay]

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<div>Originally Posted by <strong>SM</strong></div>
<div style="font-style:italic;">MK, there is actually a lot of research going on now and in the past few years with regards to the shifting epidemiology and evolutionary changes in Bordatella spp.. The current vaccines contain antigenic components for 3 pertussis antigens, not just the pertussis toxin; Filamentous hemagglutinin which protects against filamentous hemagglutinin adhesion, a virulence factor that allows bacterial colonsiation of respiratory tract; Pertactin, another virulence factor that functions as an autotransporter for B. pertussis adherence to lung epithelium and pertussis toxin (see below), there is also fimbriae protein in some vaccines but I won't get into that right now.</div>
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Have you looked at the research on which components actually provide what?<br>
They put all the components in the vaccine because....well, why not? They think some of the components might not even actually do anything, but not knowing which ones those might be, they just leave them all in.<br>
And even if they were to figure out which components were effective for preventing disease, there's still the issue of correlates of protection being way, way, way off with pertussis.<br><br><div style="margin:20px;margin-top:5px;">
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<div>Originally Posted by <strong>SM</strong></div>
<div style="font-style:italic;">The pertussis toxin actually functions as another virulence factor that facilitates endocytosis, delays neutrophil recruitment to the site of infection and inhibits macrophagic activities. So even if pertussis toxin were the only antigen in the vaccine, if colonisation is inhibited, you are not going to get clinical infection, add to that the other antigens and the bacteria are effectively eliminated by host cell defenses</div>
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But it doesn't work! It should work just like that, but it just doesn't!<br><br><a href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=529164" target="_blank">http://www.pubmedcentral.nih.gov/art...i?artid=529164</a><br><br><div style="margin:20px;margin-top:5px;">
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<table border="0" cellpadding="6" cellspacing="0" width="99%"><tr><td class="alt2" style="border:1px inset;">When examined individually, <b>the pre- versus postimmunization bactericidal activity was not significantly different at any dilution tested for 8 of the 15 acellular vaccine recipients.</b> The individuals in the group with unchanged activity after immunization included an individual with undetectable preimmunization activity against the wild-type strain (individual 32-60), and the individual with the highest preimmunization activity (individual 26-47) (Fig. 2). These results suggest that the level of preimmunization bactericidal activity does not necessarily influence the ability to generate a postimmunization response.</td>
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<table border="0" cellpadding="6" cellspacing="0" width="99%"><tr><td class="alt2" style="border:1px inset;">However, statistically significant differences between pre- and postimmunization bactericidal activity were observed (P < 0.05) using the paired t test for at least one serum dilution for 7 of the 15 acellular vaccine recipients. Furthermore, <b>evidence of <span style="text-decoration:underline;">both improved</span> bactericidal activity <span style="text-decoration:underline;">and reduced</span> bactericidal activity after immunization was found in these seven serum samples</b>. Four individuals displayed improved bactericidal activity after immunization when serum was added at lower concentrations (1.0 or 0.10%) but not at 10% (Fig. 3). However, in addition to enhanced bactericidal activity, individuals 4-43 and 20-55 displayed evidence of blocking activity, since fewer bacteria were killed when serum was added at 10% than when serum was added at 1%. Blocking activity could occur when antibodies that do not fix complement compete with complement-fixing antibodies for access to antigen. <b>More definitive evidence of blocking was demonstrated in three other individuals (Fig. 4). For these individuals, the <span style="text-decoration:underline;">postimmunization serum samples had significantly less bactericidal activity than the preimmunization serum samples at a serum concentration of 10%</span>.</b></td>
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<table border="0" cellpadding="6" cellspacing="0" width="99%"><tr><td class="alt2" style="border:1px inset;">However, <b>in this study and other studies (19, 21), improved bactericidal responses after immunization were rarely observed,</b> possibly due to induction of antibodies that fail to fix complement. <b>The absence of vaccine-induced bactericidal activity in vitro is consistent with the observation that the pertussis vaccine is effective at preventing severe disease, likely due to pertussis toxin neutralization and blocking attachment to reduce bacterial colonization, but it is less effective at producing a sterilizing immune response (5, 18).</b></td>
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A majority of people had no protection against infection. Some even had the opposite effect. And even when the vaccine "works", a reduction in colonization without any kind of sterilizing immune response is the very best you're going to get.<br>
If the vaccine worked the way it <i>seems</i> like it <i>should,</i> there would be enhanced bacterial clearance in the vaccinated. And I agree that it seems like it <i>should</i> work like that. But it doesn't. I don't know if the "blocking" theory is correct or not. But something is going on. And that also lines up with the serology that says that <i>more than half</i> of us are catching pertussis <i>every 2 1/2 years</i>...20% of us <i>every year and a half</i>. Is there any other organism you can think of that's THAT endemic? Even seasonal flu isn't nearly that common. If humans could clear pertussis easily, or if the "immune" didn't transmit it easliy, there wouldn't be so much of it.<br><br><div style="margin:20px;margin-top:5px;">
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<table border="0" cellpadding="6" cellspacing="0" width="99%"><tr><td class="alt2" style="border:1px inset;">The pertussis vaccine was more effective but does need to be re-formulated to address the evolutionary changes that have occurred.</td>
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Why do you say the pertussis vaccine was more effective?<br>
I looked into the theory that the vaccine was failing because the bacteria was evolving a while back, and I don't think that's it. That seems to have been a popular theory in the mid-90's that quickly passed out of favor. We can go into that if you want, though, but I don't think that's it.

 

[Science Mom]

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<div>Originally Posted by <strong>mamakay</strong> <a href="/community/forum/post/8565675"><img alt="View Post" class="inlineimg" src="/community/img/forum/go_quote.gif" style="border:0px solid;"></a></div>
<div style="font-style:italic;">Have you looked at the research on which components actually provide what?<br>
They put all the components in the vaccine because....well, why not? They think some of the components might not even actually do anything, but not knowing which ones those might be, they just leave them all in.<br>
And even if they were to figure out which components were effective for preventing disease, there's still the issue of correlates of protection being way, way, way off with pertussis.</div>
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It is not quite the 'shotgun' approach you make it out to be. Pertactin for instance is an outer membrane protein which are very effective antigens for immune response. Pertactin is unfortunately the protein which seems to exhibit rapid antigenic variation which is why the vaccine needs to be re-formulated (in addition to addressing other circulating strains) and I don't think you can produce a 'one-size-fits-all' vaccine for the entire world.<br><div style="margin:20px;margin-top:5px;">
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<table border="0" cellpadding="6" cellspacing="0" width="99%"><tr><td class="alt2" style="border:1px inset;">But it doesn't work! It should work just like that, but it just doesn't!<br><br><a href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=529164" target="_blank">http://www.pubmedcentral.nih.gov/art...i?artid=529164</a><br><br>
A majority of people had no protection against infection. Some even had the opposite effect. And even when the vaccine "works", a reduction in colonization without any kind of sterilizing immune response is the very best you're going to get.<br>
If the vaccine worked the way it <i>seems</i> like it <i>should,</i> there would be enhanced bacterial clearance in the vaccinated. And I agree that it seems like it <i>should</i> work like that. But it doesn't. I don't know if the "blocking" theory is correct or not. But something is going on. And that also lines up with the serology that says that <i>more than half</i> of us are catching pertussis <i>every 2 1/2 years</i>...20% of us <i>every year and a half</i>. Is there any other organism you can think of that's THAT endemic? Even seasonal flu isn't nearly that common. If humans could clear pertussis easily, or if the "immune" didn't transmit it easliy, there wouldn't be so much of it.</td>
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I think you are trying to read too much into this study. It was an in-vitro study that was taking a 'snapshot' of one component of pertussis immunity which was complement fixation. As you can see from the results how widely variable the study group response was which would be a factor for trying to establish what the correlates of immunity really are along with a rapid disappearance of antibodies. If you are using the DeVille et al. study to extrapolate pertussis infection prevalence in the population at large, I would caution that that study was performed on a healthcare worker cohort (haven't read the fulltext yet so I won't comment further) so I believe you may be estimating the actual prevalence high. And to further convolute the issue, we need to discern between acute and subclinical infections in immune and non-immune populations. In other words, if I am immune via vaccination, I become infected but don't exhibit disease symptomology that kind of speaks in favour of the vaccine at least attenuating the disease severity doesn't it?<br><div style="margin:20px;margin-top:5px;">
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<table border="0" cellpadding="6" cellspacing="0" width="99%"><tr><td class="alt2" style="border:1px inset;">Why do you say the pertussis vaccine was more effective?<br>
I looked into the theory that the vaccine was failing because the bacteria was evolving a while back, and I don't think that's it. That seems to have been a popular theory in the mid-90's that quickly passed out of favor. We can go into that if you want, though, but I don't think that's it.</td>
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There was a nadir of pertussis infections in the early 1970's and has slowly crept up so prior to that the vaccine (albeit whole-cell) did work quite well and the switch to the acellular may or may not have been a factor for the increasing incidence. As I have stated before, antigenic drift and co-circulation of numerous strains are largely responsible for the decrease in vaccine efficacy along with short-lived immunity either natural or vaccine derived that allow for the continual circulation of <i>Bordatella</i>.<br><br>
SM

 

[CCChanel]

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<div>Originally Posted by <strong>A&A</strong> <a href="/community/forum/post/8564596"><img alt="View Post" class="inlineimg" src="/community/img/forum/go_quote.gif" style="border:0px solid;"></a></div>
<div style="font-style:italic;">They have a MMRV now???? <img alt="" class="inlineimg" src="http://www.mothering.com/discussions/images/smilies/headscratch.gif" style="border:0px solid;" title="headscratch"> Great. Just great. Make it EVEN HARDER to differentiate where a reaction is coming from.</div>
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I know...this whole thing makes me sick!! <img alt="" class="inlineimg" src="http://www.mothering.com/discussions/images/smilies/greensad.gif" style="border:0px solid;" title="greensad">