Transmission
In the past, some parents participated in “chickenpox parties” to intentionally expose their unvaccinated children to a child with chickenpox in hopes that they would get the disease. CDC strongly recommends against hosting or participating in these events. Chickenpox can be serious and can lead to severe complications and death, even in healthy children. There is no way to tell in advance how severe your child’s symptoms will be. So it is not worth taking the chance of exposing your child to someone with the disease. The best way to protect infants and children against chickenpox is to get them vaccinated.
Chickenpox is a highly contagious disease caused by the varicella-zoster virus (VZV). The virus spreads easily from people with chickenpox to others who have never had the disease or never been vaccinated. The virus spreads mainly through close contact with someone who has chickenpox.
The varicella-zoster virus also causes shingles. Chickenpox can be spread from people with shingles to others who have never had chickenpox or received the chickenpox vaccine. This can happen through close contact with someone who has shingles.
A person with chickenpox is contagious beginning 1 to 2 days before rash onset until all the chickenpox lesions have crusted (scabbed). Vaccinated people who get chickenpox may develop lesions that do not crust. These people are considered contagious until no new lesions have appeared for 24 hours.
It takes about 2 weeks (from 10 to 21 days) after exposure to a person with chickenpox or shingles for someone to develop chickenpox. If a vaccinated person gets the disease, they can still spread it to others. For most people, getting chickenpox once provides immunity for life. However, for a few people, it is possible to get chickenpox more than once; although, this is not common.
For more information about how to prevent chickenpox, see Prevention and Treatment.