Hows it possible that i never developed immunity to chicken pox by age of 22?

Are you sure?: During childhood most people your age were vaccinated against varicella. Check with your parents on your personal vaccine history. Because so many of your peers have been vaccinated chickenpox has become an uncommon disease with most non-immune persons becoming infected from individuals with shingles. If you haven't been vaccinated do so soon. Chickenpox is a nasty illness in adults.

Chickenpox immunity: Agree w/ Dr Machtinger. Ask your parents or get your vaccination records from your pediatrician. Up to 90% of adolescents and adults in the US can be expected to be immune to varicella, the virus that causes chickenpox. Chances are very high that you have immunity through vaccination or exposure to someone who have chickenpox. It is safe to give varicella vaccine to someone who is immune.