Varicella Vaccination After Natural Infection in Infancy
No, you should not give varicella vaccine to this 2-year-old child who had chickenpox at 11 months of age, as natural varicella infection provides lifelong immunity and eliminates the need for vaccination. 1
Natural Immunity Supersedes Vaccination
- Natural varicella infection confers lifelong immunity, making subsequent vaccination unnecessary regardless of the age at which the infection occurred 1
- The American Academy of Pediatrics explicitly states that once a child fully recovers from varicella, no additional varicella vaccination is needed 1
- This principle applies even when the infection occurred before the typical vaccination age of 12-15 months 2, 3
Documentation of Immunity
While the guidelines emphasize that only written documentation of vaccine administration constitutes valid proof of immunity for vaccination purposes 2, natural infection history serves as evidence of immunity through a different mechanism:
- A reliable history of chickenpox is considered acceptable evidence of immunity 2
- The child's documented infection at 11 months provides this evidence
- No serologic testing is required to confirm immunity after documented natural infection
Why This Child Doesn't Need Vaccination
The standard two-dose varicella vaccination schedule (first dose at 12-15 months, second dose at 4-6 years) is designed for susceptible children who lack a reliable history of chickenpox 2
- The vaccine is specifically recommended "for susceptible children (e.g., those who lack reliable history of chickenpox)" 2
- This child is no longer susceptible, having already experienced natural infection
- Natural infection provides superior and more durable immunity than vaccination
Important Caveat
The only scenario where vaccination might be considered after apparent natural infection is if there is significant doubt about the diagnosis of the prior illness. However, if chickenpox was properly diagnosed at 11 months (typically characterized by the classic vesicular rash), the child has established immunity and requires no vaccination 1.