Thank you for your query.
The chances of getting chickenpox
for a second time after getting it is almost zero percent.
Different doctors have different opinions on the treatment of chickenpox.
You can follow the second doctor advise and take acyclovir
medication as advised by him as if it is started within 48 hours of onset of the disease, it will deccrease the severity.
Once you get chickenpox, the vaccination
is not required and there is no any vaccine available to prevent the occurence of shingles
once you get chickenpox.
Hope I have answered your query.