About Chickenpox
Chickenpox is highly infectious.
It is caused by a virus called varicella zoster and most
children will get it before they are 4 years old.
You can catch chickenpox all year round but it is most common in
winter and spring.
The virus is spread easily through touching broken chickenpox
blisters and also by coughs and sneezes. Children will be
infectious from 1-5 days before the rash appears
till the last blister crusts over. The time from catching the virus
to the first symptoms appearing can be 10-21
days.
It is possible to catch chickenpox more than once but this is
very rare. This is because our immune systems make antibodies that
fight and overcome the virus. Both then stay in our bodies for the
rest of our lives.

Radio interview about chickenpox with media
medic Dr Rob
Hicks