- Adolescent Vaccination Recommendation: Adolescents who were not fully vaccinated or have no history of immunity from the disease should get two doses of the chickenpox vaccine.
About varicella (chickenpox)
Chickenpox is caused by the highly contagious varicella zoster virus. It is spread by coughing and sneezing, and by direct contact with skin lesions. The risk for transmission of chickenpox among school-aged children, college students, and students in other post-secondary educational institutions can be high because of the likelihood of contact between people in this setting.
Chickenpox can lead to severe complications, including bacterial infection of the skin from the lesions, swelling of the brain, and pneumonia. Once a person has had chickenpox, the virus can reactivate later in life to cause a painful condition called shingles, marked by a blistering rash.
Most, but not all, infected individuals have a fever, which develops just before or when the rash (itchy blisters on the body) appears. A person with chickenpox is contagious one to two days before the rash appears and until all the blisters have formed scabs. Chickenpox typically develops 10 to 21 days after exposure.
Two doses of the vaccine are approximately 98 percent effective at preventing chickenpox. In the small number of people who are vaccinated, but still get chickenpox, the vaccine lessens the severity of their illness.