The purpose of screening is early diagnosis and treatment. Screening tests are usually given to people who do not have current symptoms, but who may be at high risk for certain diseases or conditions.
In the case of chickenpox, screening can be done to see whether you’ve acquired an immunity to the disease.
—A blood sample is taken and sent to a lab. Levels of antibodies are measured in the blood to see if you have developed immunity to chickenpox from an unrecognized previous infection or a forgotten immunization.
People who have had chickenpox usually develop immunity to it. Since 1995, a chickenpox vaccine has been available. For this reason, the National Immunization Program recommends that if you are unsure if you’ve ever had chickenpox or been vaccinated, you should talk to your doctor about having a blood test to determine whether or not you have immunity. If the tests are negative, you are not immune. In most cases, you should then receive the chickenpox vaccine to protect you from getting chickenpox.
Vaccination is particularly important for adolescents and adults, for whom infection with chickenpox may be severe or life threatening.