A mother presenting with active varicella infection (chickenpox) after exposure to her child—should she receive varicella vaccine, varicella‑zoster immune globulin (VZIG), or defer vaccination?

Management of Mother with Active Varicella Infection

Do not administer varicella vaccine or VZIG to the mother with confirmed active chickenpox—both interventions are contraindicated once the rash has appeared. 1

Why Vaccination and VZIG Are Inappropriate

Vaccine Contraindication

• Varicella vaccine is a live-attenuated vaccine that is absolutely contraindicated during active infection—it is intended for pre-exposure prevention or post-exposure prophylaxis (within 3-5 days of exposure) in susceptible individuals, not for treatment of established disease. 1
• Once the characteristic vesicular rash appears, the window for prophylactic intervention has closed; vaccination at this stage provides no benefit and violates fundamental vaccine safety principles. 1
• After recovery from natural varicella infection, the mother will have acquired natural immunity and does not require subsequent vaccination. 1

VZIG Contraindication

• VZIG is indicated only for susceptible (non-immune) persons within 96 hours of exposure to prevent disease before infection is established. 1
• Once active infection with visible rash is confirmed, VZIG has no therapeutic role—the mother is already infected and symptomatic. 2
• VZIG works by providing passive antibodies to prevent or attenuate infection; it cannot reverse established disease. 2

Correct Management of the Mother

Supportive Care

• Management shifts to supportive care and monitoring for complications once the rash appears, not prophylactic interventions. 1
• Monitor for severe complications including pneumonia (occurs in up to 25% of pregnant women with varicella), which carries significant maternal morbidity and mortality risk. 3

Antiviral Therapy Consideration

• If the mother is pregnant, oral acyclovir 800 mg five times daily should be initiated within 24 hours of rash onset to reduce severity of maternal disease, as pregnant women are at higher risk for severe varicella and complications. 3
• Acyclovir is FDA Pregnancy Category B with no increased birth defects documented in 596 first-trimester exposures. 3

Infection Control

• Implement airborne and contact precautions—the mother is infectious from 2 days before rash onset until all lesions are completely crusted and dry. 1
• Maintain isolation until all lesions have crusted to prevent transmission to other susceptible household members. 1

Critical Management of Household Contacts

Assess Immunity Status of All Household Members

• Immediately identify which household contacts (partner, other children) are susceptible to varicella. 1
• Evidence of immunity includes: documented 2-dose varicella vaccination, laboratory-confirmed IgG positivity, or healthcare-provider-verified history of varicella or herpes zoster. 2

Susceptible Household Contacts

• Administer varicella vaccine within 3-5 days of exposure to susceptible household contacts to modify disease severity—this is the appropriate use of post-exposure vaccination. 1
• Household exposure represents the highest transmission risk, with approximately 85% (range: 65-100%) of susceptible household contacts developing varicella after exposure. 2, 4

High-Risk Susceptible Contacts Require VZIG

• High-risk individuals who cannot receive vaccine—including immunocompromised persons, pregnant women, or premature infants—should receive VZIG within 96 hours of exposure to prevent severe disease. 2, 1
• For pregnant women without immunity who are exposed, VZIG reduces infection rate from >70% to approximately 30% and markedly decreases severe outcomes such as pneumonia. 2

Common Pitfalls to Avoid

• Do not confuse post-exposure prophylaxis with treatment of active disease—once the rash appears, prophylactic interventions (vaccine or VZIG) are no longer appropriate for the infected individual. 1
• Do not delay assessment of household contacts—the 96-hour window for VZIG and 3-5 day window for vaccine effectiveness are critical time-sensitive interventions. 2, 1
• Do not assume all household members are immune—actively verify immunity status rather than relying on history alone, as history of disease is unreliable. 1