evidence: In the United States, all people, including those traveling or living abroad, should be assessed for varicella immunity; people who do not have evidence of immunity should receive age-appropriate vaccination if they do not have contraindications to vaccination. Vaccination against varicella is not a requirement for entry into any country, including the United States, but people who do not have evidence of immunity (Box 5-08) should be considered at risk for varicella during international travel. [...] CDC recommends administering postexposure varicella vaccine to unvaccinated healthy people aged ≥12 months without other evidence of immunity, to prevent or modify the disease. Administer the vaccine as soon as possible ≤5 days after exposure to rash, if the exposed person has no contraindications. Among children, protective efficacy was reported as ≥90% when vaccination occurred ≤3 days of exposure. Administration of a second postexposure dose is recommended for exposed people who previously received 1 dose, so their vaccinations are current and to best protect against future exposures. CDC recommends that people without evidence of immunity who have contraindications to vaccination and who are at risk for severe varicella and complications receive postexposure prophylaxis with varicella-zoster immune globulin. The varicella-zoster immune globulin product licensed in the United States is VariZIG.