Varicella vaccine

Routine vaccination:

• Minimum age: 12 months
• Administer the first dose at age 15 through 18 months and the second dose at least 3 months later.
• The second dose may be administered before age 4 years, provided at least 3 months have elapsed since the first dose. If the second dose was administered at least 4 weeks after the first dose, it can be accepted as valid.
• The risk of breakthrough varicella is lower if given 15 months onwards.

Catch-up vaccination:

• Ensure that all persons aged 7 through 18 years without 'evidence of immunity' have 2 doses of the vaccine.
• For children aged 12 months through 12 years, the recommended minimum interval between doses is 3 months. However, if the second dose was administered at least 4 weeks after the first dose, it can be accepted as valid.
• For persons aged 13 years and older, the minimum interval between doses is 4 weeks.
• For persons without evidence of immunity, administer 2 doses if not previously vaccinated or the second dose if only 1 dose has been administered.
• 'Evidence of immunity' to varicella includes any of the following:
  • documentation of age-appropriate vaccination with a varicella vaccine
  • laboratory evidence of immunity or laboratory confirmation of disease
  • diagnosis or verification of a history of varicella disease by a health-care provider
  • diagnosis or verification of a history of herpes zoster by a health-care provider