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Chickenpox Information

Chickenpox Information

Chickenpox (varicella-zoster virus) is a very contagious viral illness, and it is possible for an individual to get chickenpox even if they are vaccinated. If your child has symptoms comparable with chickenpox, they will need to be seen by a physician or licensed practitioner. 


Transmission:  Chickenpox is spread from person-to-person by direct contact OR by droplet or airborne spread from the respiratory tract of the infected person.  


Chickenpox Incubation Period:  After an exposure, it can take anywhere from 10-21 days for symptoms to begin.


Symptoms:  Mild fever, headache, feeling tired, and an itchy blister-like rash. The rash first appears on the chest, back, and face. It then spreads over the entire body. The rash lesions will typically form a scab.


Infectious Period:  Individuals with chickenpox may be contagious 1-2 days before the onset of the rash, and not more than 5 days after the onset of the rash OR until all lesions have crusted over.


School Exclusion:  The individual with chickenpox may return to school when there are no new lesions forming and when all lesions are crusted. This typically occurs by day 6 after the onset of the rash.


For those exposed to a confirmed case:  Those who have been exposed to chickenpox and have not previously had chickenpox or received the varicella vaccine should contact your healthcare provider. Susceptible individuals should be considered infectious 10-21 days following exposure. Those with serious medical conditions or who are pregnant should ask their provider about preventative therapy availability.  



In Missouri, all children 12 months and older attending childcare or school must be vaccinated, have a verified history of the illness, or have an appropriate exemption on file with the nurse.

  • Two doses of the varicella vaccine are recommended for children:

1st dose between 12-15 months of age

2nd dose between 4-6 years of age

  • Older children or adolescents should also get two doses of the chickenpox vaccine if they have never had chickenpox or were never vaccinated. They should also get a second shot if they have had only one chickenpox shot.

For more information about chickenpox, please visit CDC-Chickenpox Info