Chickenpox (Varicella)

Chickenpox is a highly contagious disease caused by the varicella-zoster virus.  People with chickenpox develop a rash that turns into itchy, fluid-filled blisters which turn into scabs. The rash commonly shows up on the chest, back, and face, and spreads across the entire body. Some people develop serious complications from chickenpox which can lead to hospitalization or death.

Symptoms of the disease include:

  • Itchy, blister-like rash
  • Fever
  • Tiredness
  • Loss of appetite
  • Headache


Chickenpox is highly contagious and is spread through close contact with someone who has the disease. It takes about 2 weeks after exposure for a person to develop chickenpox. A person with chickenpox is contagious 1 to 2 days before forming a rash and until all lesions have scabbed over.

After chickenpox, the virus remains in the body and may cause shingles later in life. People with shingles can spread the virus to those who never had chickenpox or to those who haven’t been vaccinated.

Scientific term

  • Varicella

Generic term

Those at high risk for chickenpox complications include:

  • Infants
  • Adolescents
  • Adults
  • People who are pregnant
  • People with weakened immune systems

Groups at risk

  • All

Vaccine Information

Varicella vaccine can prevent or reduce the severity of chickenpox. Two doses of chickenpox vaccine are more than 90% effective at preventing the disease. Vaccination protects yourself and others in your family and community, especially for those who cannot get vaccinated.

Vaccine information statements

Related information

Centers for Disease Control and Prevention: