Merck Frosst
Patients and Caregivers

Vaccine-Preventable Diseases

Chickenpox

How is chickenpox spread?

Chickenpox is usually spread through:

  • the air, by coughing or sneezing
  • direct contact with blisters that form on the skin

Infected persons often spread chickenpox even before the rash appears. They are considered contagious from two days before the rash appears until all the blisters have scabbed over. Children may be infected without you even realizing it.

This site is for residents of Canada. / This site was updated on October 26, 2011.