According to the ACIP, what constitutes adequate evidence of immunity to varicella?

Adequate evidence of immunity to varicella, according to the Advisory Committee on Immunization Practices (ACIP), includes the diagnosis of chickenpox or shingles by a healthcare provider. This option recognizes that a clinical diagnosis is a reliable indicator of immunity, as it reflects the body's previous exposure to the varicella-zoster virus, either through infection or the immune response generated by the disease.

Individuals who have had chickenpox typically develop lifelong immunity. Therefore, a documented diagnosis from a healthcare professional serves as appropriate evidence that the individual is immune to varicella, as it confirms they have previously contracted the virus and subsequently built a defense against it.

While vaccination is also critical for immunity, certain vaccinations may not provide immunity if an individual does not respond adequately, making the diagnosis by a healthcare provider a stronger assurance of immunity. Other options might suggest various forms of evidence related to vaccination or birth date, but they do not serve as definitive proof of immunity in the same manner as a confirmed diagnosis does.