Modelling measles re-emergence as a result of waning of immunity in vaccinated populations - Page 3

[Juvysen]

Originally Posted by ema-adama

I cannot think of any reason why this would happen. Unless it was in sheer ignorance. Which I guess happens often enough. But I just do not see the measles vaccine stopping any time soon. And I see boosters becoming part of an adult schedule.

The big question, in my mind, is how many adults will get their boosters in a timely fashion. I think THAT will make all the difference. I don't know too many adults in my life that get their vaccinations on schedule past college...

[ema-adama]

Originally Posted by Juvysen

The big question, in my mind, is how many adults will get their boosters in a timely fashion. I think THAT will make all the difference. I don't know too many adults in my life that get their vaccinations on schedule past college...

What I think could be interesting is selling the idea to the public. A public that is more educated and not shy to ask questions. I think it will be a very reasonable question to ask why an adult booster is now needed when it was not part of the original plan.

[shuttlt]

You wouldn't need anything like 100% take up at first. Just enough to keep you ticking over with herd immunity. It's not as if we don't arrange things like this for cancer screenings. Getting sufficient take up in the long term would be a challenge and getting over the PR problems associated with vaccines would also need to be addressed.

The recent posts about a powdered measles vaccine perhaps point the way. Getting away from injections seems to me like a helpful step.

*****
Not that I am AT ALL advocating any kind of non-choice based vaccine program. Choice and information are key! :

[Th1Th2]

Originally Posted by ema-adama

Quote:
Although waning of humoral immunity in vaccinees is widely observed, re-emergence of measles in highly vaccinated populations depends on parameters for which better estimates are needed.

This is the one of the devastating effects of vaccination: The enhancement and prolongation of abnormal immune response particularly the humoral immunity.

[Dmitrizmom]

What... you mean the MMR booster that I HAD to get to start college wasn't mandatory? I was 18. I had had all the recommended doses to that point.... so why did they mandate the MMR booster when I started college? Oh... that's right... they were finding outbreaks of measles in dorms at some schools and someone figured out that not everyone had positive titres for the measles antibody...ie the vaccine has stopped being protective against the disease (our memory cells had pooped out and needed to be re-upped).

[ema-adama]

Originally Posted by shuttlt

You wouldn't need anything like 100% take up at first. Just enough to keep you ticking over with herd immunity. It's not as if we don't arrange things like this for cancer screenings. Getting sufficient take up in the long term would be a challenge and getting over the PR problems associated with vaccines would also need to be addressed.

To be honest, I think the PR would be a nightmare when it comes to dealing with informed people. Not everyone is informed, but it will not enhance the feeling that vaccine programmes are a huge success to have adults boosters added in.

The recent posts about a powdered measles vaccine perhaps point the way. Getting away from injections seems to me like a helpful step.

I hadn't thought of it like that at all. Moving away from injections. As in removing the association. Hmmmm. Not sure I would buy that. But that is me.
*****

Not that I am AT ALL advocating any kind of non-choice based vaccine program. Choice and information are key! :

:
Although, I know that your idea and my idea of information are different at times.

[ema-adama]

http://cat.inist.fr/?aModele=afficheN&cpsidt=1647422

As measles vaccination coverage increases, the circulation of wild measles will decrease, and vaccine-induced antibody is less likely to be boosted. Thus, new epidemics, albeit milder in form, may occur in vaccinated areas which should be recognised in campaigns to eradicate measles.

This study done in Africa seems to tie in. I do not know why they think the new epidemic would be milder.
I do not see this see this being recognized in the campaign to eradicate measles. Does anyone else?

[ema-adama]

I can't cut and paste, so I'll type from this article from 1990

http://scholar.google.com/scholar?hl...=viewport&pg=1

Current vaccination policy as well as mathematical models assume that vaccine induced imunity is life long. If waning vaccine immunity does occur, changes in vaccination strategies might be necessary.

Well, some people now know that it is not life long in the absense of the wild virus cirulating in the population offering 'natural' boosters. Is this changing any policy? What needs to happen for the policy to change to ensure the population is protected?

A whole generation of people loosing their immunity would create quite a dent in the herd immunity.

[mamakay]

To be honest, I think the PR would be a nightmare when it comes to dealing with informed people. Not everyone is informed, but it will not enhance the feeling that vaccine programmes are a huge success to have adults boosters added in.

With measles, I don't think it would be too bad. People might grumble, but if "the truth" was presented in a completely transparent way, I think most people would be like "Ok, I guess."
Measles is sort of unique in this regard, though, in that when they're talking about the herd immunity end, and eventual eradication...it really can happen with measles. And there's no obvious, known abd proven downfall to eradicating measles. (compared to chickenpox, pertussis, pneumococcal species, etc where herd immunity either can't exist or has some weirdo "dark side".)

[mamakay]

Originally Posted by ema-adama

I can't cut and paste, so I'll type from this article from 1990

http://scholar.google.com/scholar?hl...=viewport&pg=1


Well, some people now know that it is not life long in the absense of the wild virus cirulating in the population offering 'natural' boosters. Is this changing any policy? What needs to happen for the policy to change to ensure the population is protected?

A whole generation of people loosing their immunity would create quite a dent in the herd immunity.

The CDC is considering adding MMR boosters for older people.

http://www.acha.org/ACIP%20Oct%2006%...ng%20notes.pdf

Questions that remain regarding the collagen outbreak:
1. Is mumps circulating endemically and is there a high accumulation of susceptibles due to vaccine failure?
2. Would a third dose of MMR be useful for outbreak prevention?
3. Can mumps be eliminated using the current MMR vaccine?

[mamakay]

Originally Posted by shuttlt

You wouldn't need anything like 100% take up at first. Just enough to keep you ticking over with herd immunity. It's not as if we don't arrange things like this for cancer screenings. Getting sufficient take up in the long term would be a challenge and getting over the PR problems associated with vaccines would also need to be addressed.

The recent posts about a powdered measles vaccine perhaps point the way. Getting away from injections seems to me like a helpful step.

*****
Not that I am AT ALL advocating any kind of non-choice based vaccine program. Choice and information are key! :

I completely agree. When it comes to prevention, especially when part of the rationale involves "do it for your neighbor"...yes, "less invasiveness" should be a goal.
And I mean this in a "basic morality" kind of way....not just "in the best interest of public health.

I look at this:
http://www.cdc.gov/vaccines/pubs/pin...D/site-map.pdf
And it just makes me cringe. And some of those shots aren't even for the kid! It's to protect an older age group, and they expect that the kid will have to be re-vaxed himself if he wants protection in the future.

It just seems weird...and cruel.

[ema-adama]

Originally Posted by mamakay

With measles, I don't think it would be too bad. People might grumble, but if "the truth" was presented in a completely transparent way, I think most people would be like "Ok, I guess."

I guess it depends on how much you know about the assumptions made that were not accurate.

Measles is sort of unique in this regard, though, in that when they're talking about the herd immunity end, and eventual eradication...it really can happen with measles. And there's no obvious, known abd proven downfall to eradicating measles. (compared to chickenpox, pertussis, pneumococcal species, etc where herd immunity either can't exist or has some weirdo "dark side".)

No, there is no obvious known and proven downfall to eradicating measles. However, this does not mean that it will not emerge in time (annoying aurgument, I know, but with measles it seems that too much is not known. I do not think it is like smallpox).
I do not see how it is going to happen with the mathematical models showing new epidemics of measles in highly vaccinated populations. I might be missing something. But I am guessing that eradicating measles through vaccination is going to proove to be a tad more difficult than mass vaccinating the population.

[ema-adama]

Originally Posted by mamakay

The CDC is considering adding MMR boosters for older people.

Yippeeee. Not.

With regard to herd immunity this makes sense. Ie life long immunity being necessary for herd immunity.

The indignant adults who fear my child can roll up their own sleeve, or sniff it, whatever the case will be.

[mamakay]

I guess it depends on how much you know about the assumptions made that were not accurate.

You know, I'm not sure. People aren't objecting to the tdap, and that one actually is sort of a scam. With measles, the same scenario actually is true.

do not see how it is going to happen with the mathematical models showing new epidemics of measles in highly vaccinated populations. I might be missing something. But I am guessing that eradicating measles through vaccination is going to proove to be a tad more difficult than mass vaccinating the population

.

Maybe. We here in the US have had amazing success at measles elimination, though, so far. But we're not a highly HIV endemic population, we're not all starving, etc so what has happened here might not be applicable worldwide.

[ema-adama]

Originally Posted by mamakay

You know, I'm not sure. People aren't objecting to the tdap, and that one actually is sort of a scam. With measles, the same scenario actually is true.

I don't know what the uptake for DTaP is amoungst adults. I certainly would never have it. At least not to protect anyone from pertussis, which is the selling point. Perhaps I am way outside of the parametres of what is considered 'average person', when it comes to deciding whether to vaccinate or be vaccinated.

.

Maybe. We here in the US have had amazing success at measles elimination, though, so far. But we're not a highly HIV endemic population, we're not all starving, etc so what has happened here might not be applicable worldwide.

It is maybe for now from what I know. I will be interested to see what happens in the next 60 years. (I should still be around then ) For now I am happy I had measles as a child and I hope my children will have measles.

[mamakay]

Perhaps I am way outside of the parametres of what is considered 'average person', when it comes to deciding whether to vaccinate or be vaccinated.

I'm sure you are.

It is maybe for now from what I know. I will be interested to see what happens in the next 60 years.

True.
But...give enough people MMR boosters often enough and it should "work". There's basically no way it wouldn't. If they were able to throw an MMR-type thing into something like Flumist, I bet they could get a lot of people vaxed.

[ema-adama]

mamakay, do you have a clear understaning of what vaccine modified measles is? I just do not have a clear idea of how this factors into re-emerging measles.