implication of positive CP titre after vaccine...

[nicolebeth]

I was wondering if anyone had any information about this. DD's titres came back as "immune" for CP (and measles). She had the vaccine in 2003, and probably was exposed to CP in 2005 and 2006.

What does an immune titre actually mean since her immunity is from the vaccine? Do most kids get an immune within four years of the vaccine, but then go on to get CP a few years later? Or, does this mean the shot "worked" for her, and her immunity will wane at some distant point? Like as a teen or older? Or, is it possible that she had a subclinical case of CP? (Would the blood test even have been able to tell that?)

My question is: Does having an immune titre really mean anything for DD's health? Forgetting the vaccination issue...obviously, it means that she has no pre-K shot requirement (which we weren't going to give her anyway).

DH and I are trying to figure out whether we need to behave as if she's had CP (and forget about it) or as if she hasn't (try to have her get it!) DS is two, and hasn't had the shot, so it's possible that it may be in the house in the next few years anyhow.

Thanks--hopefully, I wasn't being too confusing.

[mamakay]

It's hard to say what the future holds, because it's hard to say what will happen with chickenpox in the future in the US. If the CDC's second dose of varicella drives the incidence of chickenpox back down for a while in the US, then her immunity might wane. If the second dose doesn't end up working very well, and your daughter keeps getting exposed periodically, then she'll probably stay immune.

What does an immune titre actually mean since her immunity is from the vaccine? Do most kids get an immune within four years of the vaccine, but then go on to get CP a few years later? Or, does this mean the shot "worked" for her, and her immunity will wane at some distant point? Like as a teen or older? Or, is it possible that she had a subclinical case of CP? (Would the blood test even have been able to tell that?)

One dose does make some kids pretty immune for quite a while. Some kids are immune for a while and then end up getting CP later. Or she might have had a subclinical case, or just being exposed could have really boosted her immunity in a way that comes very close to "natural" chickenpox. And the bloodtest won't/can't tell you which it was.
There's really just no way to know for sure.

[talk de jour]

That means that right now she's immune, and you have no idea of knowing if or when the immunity will wear off.

If you're that concerned, get her titers checked every year or so.