On Fri, 18 Jul 2003 18:21:12 GMT, Wendy Marsden
wrote:

Because my experience with chicken pox is that it is an inconvenient but
not terrible childhood disease that is much worse if you get it as an
adult, and I'm worried that the vaccine will wear off, causing the adult
to get a much worse case than he would have as a child.

It is likely that breakthrough infections in vaccinated adults will be
mild, as they are in children.

By the way, I had to have a rubella booster shot as an adult - the vaccine
had worn off.

It's important to know that the determination that your immunity from
the vaccine had waned was probably based on your serum antibody level,
which is a poor surrogate marker for actual immunity. Rechallenge you
with actual rubella virus and you may have a proper, robust anamnestic
protective immune response despite previously undetectable antibody
levels.

I also feel confident that I could adequately remove him from the company
of adults who are not immune so that I would be endangering no-one else.

I would not be so confident, as chickenpox is contagious for a few
days before the first lesions appear, and frequently with chickenpox
the parents were not aware of a recent exposure.

PF