Varicella Vaccination After Recent Chickenpox Infection
Varicella vaccination is unnecessary and not recommended for an 18-month-old who had confirmed chickenpox six months ago, because natural varicella infection provides lifelong immunity that is superior to vaccine-induced immunity. 1
Evidence of Immunity Eliminates Need for Vaccination
- A documented history of varicella disease verified by a healthcare provider constitutes evidence of immunity and is a valid reason to withhold varicella vaccination. 1
- Natural varicella infection provides lifelong immunity that eliminates the need for any varicella vaccination. 1
- The Advisory Committee on Immunization Practices (ACIP) explicitly recognizes healthcare provider verification of varicella history as evidence of immunity. 1
Safety Considerations
- While administering varicella vaccine to a child with prior natural infection is not contraindicated from a safety standpoint, it provides no immunological benefit because natural infection already induces complete immunity. 1
- Vaccinating a child who already has immunity from natural infection unnecessarily consumes healthcare resources without any clinical advantage. 1
Documentation Requirements
- Ensure that the healthcare provider's verification of the chickenpox infection is documented in the medical record to prevent future unnecessary vaccination attempts. 1
- Written documentation of healthcare provider verification should be maintained, as parental reporting alone may be insufficient for official immunity verification. 1
Important Distinction from Standard Vaccination Schedule
- The routine two-dose varicella vaccination schedule (first dose at 12-15 months, second dose at 4-6 years) applies only to susceptible children who have never had chickenpox. 1
- Children with healthcare-provider-verified prior varicella infection are considered immune and do not require these vaccinations. 1