Chicken pox vac for 5yo who has had mild chicken pox?

[Superduper13]

Hi there,
I have booked my 1 yo to get the chicken pox vaccination and I am wondering whether to get my 5yo done too.
He had a very mild dose of chicken pox when he was 3. Very few spots and abit of a temp but generally well. Is he still at risk of getting chicken pox ? Is it worth getting him vaccinated?
Any advice or suggestions for reading would be appreciated. Thanks

Why not instead, get him checked for chickenpox immunity? Much better than putting more crap in him if his first bout totally protected him.