Does or does not pertussis vaccine prevent transmission?

[sophi4ka]

I am totally confused on this one, cause I've read confusing statements:

Some claim that the pertussis vaccine is developed only against the toxin (the one that causes the cough when the bacteria is dying), thus the vaccine will prevent the vaccinated person from getting the awful cough while he/she will still be able to spread the disease around. This will make the campaign of "I did it for my baby" totally misleading.

However, some claim that the vaccine actually protects against the pertussis bacteria too, thus decreasing the likelihood of the vaccinated person catching the disease at all and spreading it around.

So which statement is correct?

Thank you
Sophie

[heathergirl67]

Here's a couple of things that I could find

Unfortunately they're just abstracts, but with a little digging you might be able to find the whole articles.
1. http://journals.lww.com/pidj/Abstrac...iology,.3.aspx

Conclusions: Pertussis is on the rise, particularly in adolescents. Booster vaccination of adolescents with less-reactogenic acellular pertussis vaccines appears to be the most logical approach to disease prevention in adolescents and reduced transmission to young infants.

My take on it: Immunization leads to less chance that the immunized person will get infected at all with the pertussis disease. And of course, they can't pass it if they never catch it.

2. http://jama.ama-assn.org/cgi/content/abstract/275/1/37

My take on it: Households who were immunized got infected less than households who were not.

HTH!

[MountainMamaGC]

Getting immunized does not make you immune to the bacteria. Its a toxoid vaccine. It makes you immune to the toxin the bacteria produces. The toxin is an irritant and it makes you cough.

You can still be a carrier of the bacteria, you will just be asymptomatic. If you are asymtomatic you wont be coughing so you wont be spreading it as much, but its still present in your secretions and you can still spread it that way.

[INF-ss]

Getting immunized does not make you immune to the bacteria. Its a toxoid vaccine. It makes you immune to the toxin the bacteria produces. The toxin is an irritant and it makes you cough.

BTW, acellular pertussis vaccines also contain filamentous hemagglutinin (FHA) which is the surface-associated protein of B. pertussis.

[Sileree]

Re:

"Immunization leads to less chance that the immunized person will get infected at all with the pertussis disease. And of course, they can't pass it if they never catch it."

With some other vaccines it works that way, but not with DTaP/Tdap. It supposedly lessens symptoms (this is arguable in my opinion after reading studies about observer bias for this vaccine) but does not prevent infection.

http://pediatrics.aappublications.or...act/104/6/1381

"...all pertussis vaccines tend to modify duration and severity of disease rather than completely preventing illness."

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

"It is becoming clear that B. pertussis bacteria are capable of infecting and proliferating in a large proportion of vaccinated individuals. In one study, 33% of the exposed individuals receiving the highly effective five-component acellular pertussis vaccine had evidence of infection and 24% coughed for 21 days or more. In the same study, 82% of individuals receiving a licensed whole-cell vaccine had evidence of infection and 65% coughed for 21 days or more."

http://www.cdc.gov/ncidod/eid/vol6no5/srugo.htm

"The whole-cell vaccine for pertussis is protective only against clinical disease, not against infection. Therefore, even young, recently vaccinated children may serve as reservoirs and potential transmitters of infection."

The reason is the P portion of DTaP and Tdap doesn't induce bactericidal activity in vaccinated individuals. So vaccinating someone doesn't make them clear the bacteria from their lungs.

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

"We found no evidence that acellular vaccines promoted antibody-dependent killing by complement of enhanced phagocytosis by neutrophils."

Thus going around and vaccinating adults for pertussis isn't going to stop them from carrying the bacteria and transmitting it to babies. The vaccine doesn't work that way. The point of the vaccine is to be "immune" to the toxin the bacteria release that irritates the lungs (thus making you cough), so that you cough less severely and for 5-10 days less than an unvaccinated person.

Here are some links to previous threads where this has been discussed before:

http://www.mothering.com/discussions....php?t=1226677

http://www.mothering.com/discussions...d.php?t=998940

http://www.mothering.com/discussions...d.php?t=806782

http://www.mothering.com/discussions...d.php?t=900456

[INF-ss]

Originally Posted by Sileree

The reason is the P portion of DTaP and Tdap doesn't induce bactericidal activity in vaccinated individuals. So vaccinating someone doesn't make them clear the bacteria from their lungs.

So where did the vaccinated acquire the bacteria from?

[sophi4ka]

Originally Posted by Sileree

Re:

Thus going around and vaccinating adults for pertussis isn't going to stop them from carrying the bacteria and transmitting it to babies. The vaccine doesn't work that way. The point of the vaccine is to be "immune" to the toxin the bacteria release that irritates the lungs (thus making you cough), so that you cough less severely and for 5-10 days less than an unvaccinated person.

But what about that FHA component of the vaccine? Isn't it the one that makes the vaccine also effective against the bacteria itself, not only the toxin?

[Sileree]

Originally Posted by INF-ß

So where did the vaccinated acquire the bacteria from?

The disease is endemic, and always has been. The bacteria circulate and everyone is exposed every 2-5 years according to serological studies. There is no herd immunity effect with this vaccine, so everyone, whether vaccinated or not, spreads it around.

http://www.ncbi.nlm.nih.gov/pubmed/16805225

"Pertussis is considered an endemic disease, characterized by an epidemic every 2-5 years. This rate of exacerbations has not changed, even after the introduction of mass vaccination – a fact that indicates the efficacy of the vaccine in preventing the disease but not the transmission of the causative agent (B. pertussis) within the population."

[Sileree]

Originally Posted by sophi4ka

But what about that FHA component of the vaccine? Isn't it the one that makes the vaccine also effective against the bacteria itself, not only the toxin?

Theoretically it should, but it doesn't seem to in reality.

Vaccines don't contain adenylate cyclase toxin (ACT).

This is a post from a previous thread that explains how this is relevant:

http://mothering.com/discussions/sho...4&postcount=10

[INF-ss]

Originally Posted by Sileree

Theoretically it should, but it doesn't seem to in reality.

Vaccines don't contain adenylate cyclase toxin (ACT).

This is a post from a previous thread that explains how this is relevant:

http://mothering.com/discussions/sho...4&postcount=10

There are at least 20 antigens in the B. pertussis
organism including ACT that are immunogenic and that can be used in future vaccines.

Of course, only time will tell.

[Deborah]

Originally Posted by INF-ß

There are at least 20 antigens in the B. pertussis
organism including ACT that are immunogenic and that can be used in future vaccines.

Of course, only time will tell.

Time has told. This vaccine has been in use for over 60 years. Pertussis is still endemic.

Perhaps they are dreaming that vaccinating 90% or 95% of the total population will have an effect? But adults simply aren't compliant with vaccination on that scale.

I don't think there is a hope of stopping pertussis with the current vaccine.

[sophi4ka]

Originally Posted by Sileree

Theoretically it should, but it doesn't seem to in reality.

Vaccines don't contain adenylate cyclase toxin (ACT).

This is a post from a previous thread that explains how this is relevant:

http://mothering.com/discussions/sho...4&postcount=10

I should have gotten a degree in immunology
I read the post several times and still don't quite get what it says

[japonica]

Originally Posted by Deborah

Time has told. This vaccine has been in use for over 60 years. Pertussis is still endemic.

Perhaps they are dreaming that vaccinating 90% or 95% of the total population will have an effect? But adults simply aren't compliant with vaccination on that scale.

I don't think there is a hope of stopping pertussis with the current vaccine.

Especially when the pertussis bacteria are changing so much and so rapidly...in response, at least in part, to vaccination programs...

http://www.ncbi.nlm.nih.gov/pmc/arti...7/?tool=pubmed

Changes in the genomic content of circulating Bordetella pertussis strains isolated from the Netherlands, Sweden, Japan and Australia: adaptive evolution or drift?
Audrey J King, Tamara van Gorkom, Han GJ van der Heide, Abdolreza Advani, and Saskia van der Lee

Additionally, the CGH data revealed that the genome size of B. pertussis strains has decreased progressively over a period of 60 years. Our results show that B. pertussis is dynamic and is continuously evolving. This process seems to be influenced by adaptive evolution.

I can't post all the nuts and bolts of it here, but it's definitely an interesting read...

[majormajor]

here's a link to an article that provides evidence for the ability of the vaccine to prevent transmission: http://rspb.royalsocietypublishing.o...2010.0994.full

it's an interesting article. basically, the authors examine the size of the period of cyclical infection (pertussis is one of those diseases that peaks every few years) and demonstrate how it reliably grows after the introduction of mass immunization. an increase in the period supports the hypothesis that the vaccine does actually decrease transmission. clever.

it also seems to me that since the only way for the vaccine to reduce the incidence of pertussis amongst the too-young-to-vaccinate (ie, less than 2 months old) is by preventing transmission, than looking at pre- and post-vaccine incidence in that age group would give more proof for the prevention of transmission. but, i looked, and can't find hard numbers for pre-vaccine incidence in that age group alone. seems reasonable to think that there's less since mortality hit a low of 4 deaths in one year in the US, but we need the actual pre-vaccine numbers to say for sure.

[Deborah]

When you look at the CDC site (on the parent's pages) they come up with a very high death rate pre-vaccine, but they don't give a year. So pre-vaccine could be anywhere from 1910 to ?

http://lingli.ccer.edu.cn/he2007/rea..._product_1.pdf

This article gives the best evaluation of the overall trends I've been able to find. See the charts on page 418 and on page 423 and then read from there to the end of the article.

[ma2two]

Originally Posted by sophi4ka

thus the vaccine will prevent the vaccinated person from getting the awful cough while he/she will still be able to spread the disease around. This will make the campaign of "I did it for my baby" totally misleading.

I guess for legal reasons, the manufacturer actually admits right in their advertisement that their advertisement is misleading.
"It is unknown whether immunizing adolescents and adults against pertussis will reduce the risk of transmission to infants."
http://www.adacel-locator.com/index....E&P=HowS_pread

Edit: Sanofi Pasteur has since taken down that link. Here is a different one: http://www.vaccineplace.com/support/brochure/adacelpatientbrochure.pdf (page 5)

Edited by ma2two - 5/15/11 at 11:11pm

[Turquesa]

Originally Posted by ma2two

I guess for legal reasons, the manufacturer actually admits right in their advertisement that their advertisement is misleading.
"It is unknown whether immunizing adolescents and adults against pertussis will reduce the risk of transmission to infants."
http://www.adacel-locator.com/index....E&P=HowS_pread

HOLY #$%$#%! Thank you for sharing this! What an eye-opener.

[Chris P]

Natural infection of B. Pertussis uses ACT to colonize the lungs. This colonization is important as the body will remember it if re-infected not to mention ACT allows the B. Pertussis Toxin to clear the lungs. Two vital components of disease control which is exactly why a healthy host is able to beat infection with out any serious longterm effects and also gains 20 years of immunity and less complications if any in the future. 

The vaccine lacks ACT. Pubmed studies have even shown that this component is lacking in the current vaccine and would be a great addition. Either cost, ignorance, biochemically unable to add or simply not considered are some of the possible reasons. Your looking at several hundred millions to make a vaccine, Phase I, II, III trials would take years, blah blah blah.

If ACT is not there the recently vaccinated will be unable to clear the infection from their lungs and become either sympomatic or asymptomatic carries of infection as the CDC acknowledges.

The strain of Pertussis has changed as several countries have confirmed aswell.

The question now becomes....if this vaccine is questionable in it's ability to prevent infection and if it indeed is spreading infection...are recently vaccinated able to infect their newborn when their tiny lungs are so small and unable to fight off lung infection. I would not argue that several hundreds of thousands of cases occur yearly in the US and diagnosed as one of the 30 other similar disease that include coughing, slight fever, etc etc.

[japonica]

Originally Posted by Turquesa 

Originally Posted by ma2two

I guess for legal reasons, the manufacturer actually admits right in their advertisement that their advertisement is misleading.
"It is unknown whether immunizing adolescents and adults against pertussis will reduce the risk of transmission to infants."
http://www.adacel-locator.com/index....E&P=HowS_pread

HOLY #$%$#%! Thank you for sharing this! What an eye-opener.

The Boostrix product information says this as well:

Boostrix Product Information

There are currently no data which demonstrate a reduction of transmission of pertussis after immunisation with BOOSTRIX. However, it could be expected that immunisation of immediate close contacts of newborn infants, such as parents, grandparents and healthcare workers, would reduce exposure of pertussis to infants not yet adequately protected through immunisation.

There's no scientific proof that this product reduces transmission, but theoretically, it could be expected...

[ma2two]

That's why Sanofi Pasteur puts a disclaimer on their Tdap vaccine ads, saying, "It is unknown whether immunizing adolescents and adults against pertussis will reduce the risk of transmission to infants." http://www.vaccineplace.com/support/brochure/adacelpatientbrochure.pdf (page 5)

Originally Posted by sophi4ka 

Some claim that the pertussis vaccine is developed only against the toxin (the one that causes the cough when the bacteria is dying), thus the vaccine will prevent the vaccinated person from getting the awful cough while he/she will still be able to spread the disease around. This will make the campaign of "I did it for my baby" totally misleading.
 

Edit: I re-read this thread, and saw that I said the same thing 10 months ago. But it's worth mentioning again, and there's a different link now.