Why do people get chickenpox after vaccination?
Chickenpox spreads very easily from person to person by direct contact with fluid from blisters or through the air when someone with chickenpox coughs or sneezes. The time period between exposure and the onset of illness is usually 14 to 16 days, but can range from 10 to 21 days. Chickenpox is hard to recognize in those who have been vaccinated because the rash may be very mild. Vaccinated persons who get chickenpox are infectious to others and need to stay home while ill. .
