Varicella can make you feel terrible, it did me. And, as my wedding photo's will testify, it stopped me and Mrs Ginge going on honey-moon.
However, despite the text books warning of potentioal complications (encephalopathy, pneumonia etc), the effects are generally self limiting.
I suspect the main reason for vaccination is to protect pregnant ladies who have never been exposed to the virus, and the immuno-compromised.
