Can varicella vaccine be used as postexposure prophylaxis for a 9-month-old who was exposed to herpes zoster?

Varicella vaccine is neither approved nor recommended for children younger than age 12 months. Assuming that the child is not immunocompromised, varicella zoster immune globulin (VariZIG) is also not recommended.

ACIP does not have a recommendation for acyclovir for varicella postexposure prophylaxis. The American Academy of Pediatrics provide some guidance on this issue in the current edition of the Red Book.