(Apologies to anyone who has) but i really don't understand why anyone would give their child a vaccination against chicken pox. It isn't a dangerous virus and only takes a week or so to recover from so why not allow their immune system a chance to grow on its own. I understand that perhaps it is not pleasant to deal with a fussy/sick/uncomfortable child, and that it is upsetting to see them suffering, however without that kind of experience they will have practically no immune system of their own and will rely (as much of the world does today) on stronger and stronger Antibiotics to recover from simple illnesses that the body should be able to cope with on its own.

As a child raised with only the necessary vaccinations and minimal drug intervention for illnesses (i think i only had antibiotics twice from birth to my now 26years old) i can say that i fall sick far less than people i know who were dashed to the doctor and given a million and one different chemicals and drugs every time they had a sniffy nose.
Ok now my rant is over.

@TS- I hope your son gets through his chicken pox quickly without too much discomfort, but i definitely side with your doctor and would go with letting your son go through chicken pox naturally.

The chicken pox you get later in life isn't milder at all, it is much worse the older you are which is why a lot of people like me try to expose our kid to chicken pox naturally when they are around 2-4 years old, to get it out of the way while they are young enough to recover quickly but old enough to cope with it. To a 3-4 year old chicken pox means a light fever and around a week or so of itchiness, for a 16-18year old it can mean hospitalization.

Of course there is still the chance to get it later in life whether you go natural or vaccinate but the long term effects of getting chicken pox naturally are known (practically none, beside the minor chance of shingles later in life), the long term effects of the vaccination are not.
It is also known that if you go through natural chicken pox the chances of relapsing later in life (shingles) is very low under normal circumstances (it is usually only when the immune system is already compromised that shingles pops up). With the vaccination, i haven't read anything that convinces me that anyone knows its effective lifespan. 

I just don't agree with using drugs and vaccinations when they aren't necessary especially when a large number of the 'super-viruses' and more severe flu like bugs we have around today are purely the result of overusing medications like antibiotics. Unless they are used to prevent or cure a serious or potentially fatal disease all you are doing is sacrificing natural immune system strength for the convenience of skipping a few days of grumpiness and mild discomfort.