AIBU to ask a quick biology question?

[Valdeeves]

Sorry but need a quick answer and shamelessly posting as there's more traffic here.

I want to get kids vaccinated against chickenpox (they naturally scar very badly
due to the nature of their skin.)
There is chickenpox in my sons preschool - I found out today.
I had planned to take them Friday for the first jab.
If my son has been exposed will the jab be useless?
It is a live vaccine.
Anybody help? - the clinic has hiked the prices up to £400 for both children.
I don't want to spend that if there's no point?

Any biologists out there who can help me please?

Just to add - I had the jab as I have never had it myself.

I don't know about the jab if they have been exposed. However, I do know that the vaccine is not terribly effective. I had CP twice and DD had the jab and got CP as well. 400 quid is a lot for what is not a very effective vaccine.

I wouldn't say the jab is not effective. Almost all children here receive it and in my 7 years here I've not heard of a single vaccinated child getting cp.

Regarding it not being effective, my two DDs had it 9/10 years ago. They never developed chickenpox. They got the jab as babies.

Definitely still get them vaccinated. It's quite common to vaccinate precisely BECAUSE someone has been exposed: it does reduce the risk of getting chicken pox and if they get sick, it won't be as bad.
True the vaccine isn't as effective as some (TWO of my 3 DC got chicken pox despite being vaccinated) but it's still worth a try, and I'm told my kids got such mild cases because they'd been vaccinated.

I don't know hoe effective the vaccine is but the incubation period for cp is up to three weeks and I doubt it will prevent the illness if exposure has already occurred

I assume that the £400 is a course of two vacinnes for two children. ie. 4 jabs.

dd had one chickenpox jab costing £90 out of a course of two. She then had really mild chicken pox with just 6 spots so we did not go back for the second jab.

I was under the impression that if a child had two jabs for chickenpox then the protection was effective. In some countries children only get one jab and that is less effective.

Thank you ladies for taking the time to reply - I really appreciate it.

So I don't know if this will help but last year When I was pregnant
My dd got cp I went to the midwife as I never had it (confirmed by blood test)
They almost made a terrible mistake of giving me the live vaccine when the nurse rang the public health lab and said to give me something else as I had been exposed to cp and pregnant.
She said I need immuno something I can't remember full name! basically it is antibodies from someone else available from the hospital and gave me protection for 21 days.

If this is possible for your children it would give enough protection until they are vaccinated. The problem with cp is the contagious period, some argue it is before spots and some disagree.
The public health lab agreed it can take up to 21 days until you know you have it.
I hope it makes sense.
I never got it, despite my dd2 getting it 10 days later.