Should an 18-month-old child with a confirmed history of varicella (chickenpox) infection receive the varicella vaccine?

Varicella Vaccine Should Be Withheld in This Child

A child with confirmed prior varicella infection does not need varicella vaccination, as natural infection provides immunity and vaccination is unnecessary. 1

Evidence of Immunity

The 18-month-old child in this case has documented evidence of varicella immunity through:

• Physician-verified history of chickenpox with typical varicella rash presentation shown to the pediatrician 1
• This constitutes valid evidence of immunity according to American Academy of Pediatrics guidelines, which specify that "documentation of immunity to varicella-zoster virus includes history of varicella disease verified by a healthcare professional" 1
• Any healthcare professional can verify immunity for patients with typical disease presentation 1

Why Vaccination Should Be Withheld

Prior varicella infection provides natural immunity, making vaccination medically unnecessary. 1 The CDC explicitly states that "children who have already had chickenpox do not need varicella vaccination." 1

The guideline framework is clear:

• Evidence of immunity includes laboratory evidence, laboratory confirmation of disease, or history of varicella disease verified by a healthcare professional 1
• This child meets the third criterion with physician documentation of typical varicella rash 1
• Natural infection confers lifelong immunity in immunocompetent individuals 2

Age Considerations Are Irrelevant Here

While routine varicella vaccination is recommended at 12-15 months of age for children without evidence of immunity 3, this recommendation does not apply to children with documented prior infection. The age-based vaccination schedule (first dose at 12-15 months, second dose at 4-6 years) is designed for susceptible children, not those with established immunity 3.

Common Pitfalls to Avoid

• Do not confuse this scenario with routine vaccination schedules - the presence of documented prior infection changes the clinical decision entirely 1
• Self-reporting alone would not be sufficient - parental history without physician verification has become less reliable in the vaccine era 3, but this case has physician documentation with typical rash presentation 1
• Do not order unnecessary serologic testing - with clear physician documentation of typical varicella disease, serologic confirmation is not needed 1

Answer to the Question

The correct answer is A: Varicella vaccine withheld. 1 Options B, C, and D are all incorrect because they involve administering vaccine to a child who already has documented immunity from natural infection.