Welcome to healthcare magic!
The G6PD patients have frank contraindication for drugs that have oxidative properties, Because the hep.A&E speard through infected water and food, having two children sick from one disease is not unusual.
It is barely two weeks since your son has got the vaccine
so he is susceptible for another 7-10 days and Hep.a vaccination
does not protect against Hep.E.
kEEP CHILD HYDRATED, ENSURE HE TAKES REST ANDGET LIVER
If problem if frequent see a liver care doctor.
I hope this advise would be helpful for you.
Still if you have any queries or doubts, please write me back,
I would be happy to solve them.
Wish you a great health!