I think Oliver is a hypoallergenic cat.  My husband Steve has always
been very allergic to cats but by some strange twist of fate he has
never had an allergic reaction to Oliver.  I always had three theories
about this.  1) Oliver was so small when Steve found him that Steve was
able to build up a tolerance to his dander 2)Oliver is hypoallergenic or
3) Steve just loves him so much his body suppresses the allergic response.

My 20 year old niece was just here and she is also very allergic to cats
 just like her Uncle.  Even with allergy meds she can barely tolerate
being in the same room with a cat.  She was here for 5 days and she had
no reaction to Oliver at all.  It was amazing and it made her so happy
to be able to cuddle and love up Oliver (who ate up all the attention
like it was tuna!)

Now Steve is joking about cloning Oliver so we can always have a kitty.  :-)