Is the varicella (chickenpox) vaccine contraindicated in households with immunosuppressed persons and if not, what precautions are recommended?

Varicella Vaccine in Households with Immunocompromised Persons

Varicella vaccine is NOT contraindicated for household contacts of immunocompromised persons; in fact, it is strongly recommended to protect the immunocompromised individual by reducing the risk of wild-type virus exposure in the household. 1

Rationale for Vaccination of Household Contacts

The Advisory Committee on Immunization Practices (ACIP) and the American Academy of Pediatrics (AAP) both recommend routine vaccination of household contacts of immunocompromised persons for several important reasons:

• Immunocompromised individuals are at high risk for serious varicella infections, with severe disease occurring in approximately 30% of such persons with primary infection 1
• Vaccination of household contacts provides protection for immunocompromised persons by decreasing the likelihood that wild-type varicella-zoster virus will be introduced into the household 1
• The benefits of vaccinating susceptible household contacts significantly outweigh the extremely low potential risk for transmission of vaccine virus 1

Risk of Transmission of Vaccine Virus

The risk of transmitting the vaccine strain virus to immunocompromised household contacts is minimal:

• No cases of transmission of vaccine virus to immunocompromised persons have been documented in the postlicensure period in the United States, with >55 million doses of vaccine distributed 1
• A systematic review found that transmission of vaccine-strain virus from immunocompetent vaccinated persons occurs only when the vaccine recipient develops a rash, and even then is rare 2
• In one study, no evidence of transmission of vaccine virus was demonstrated after vaccination of 37 healthy siblings of 30 children with malignancy 1

Precautions for Household Contacts with Vaccine-Related Rash

While vaccination is recommended, some precautions should be taken:

• Vaccine recipients who develop a vaccine-related rash, particularly household contacts of immunocompromised persons, should avoid contact with the immunocompromised person until the rash resolves 1
• If an immunocompromised person is inadvertently exposed to someone with a vaccine-related rash, post-exposure prophylaxis with VZIG is not needed because disease associated with the vaccine virus is expected to be mild 1

Special Considerations

1. Pregnant household members:

   • Having a pregnant household member is NOT a contraindication for vaccinating a child in the household 1

2. Nursing mothers:

   • Varicella vaccine can be safely administered to nursing mothers who lack evidence of immunity 1
   • Studies have shown no evidence of VZV DNA in breast milk samples after vaccination 1

Important Caveats

• The varicella vaccine itself is contraindicated in immunocompromised persons (except certain HIV-infected children with CD4 ≥15%) 1
• Severe complications from vaccine-strain virus have been reported in immunocompromised individuals who were inappropriately vaccinated 3, 4
• When immunizing persons with any degree of immunodeficiency (when appropriate), only single-antigen varicella vaccine should be used, not the combination MMRV vaccine 1

Algorithm for Decision-Making

1. For household contacts of immunocompromised persons:

   • Vaccinate all susceptible household contacts without evidence of immunity
   • No waiting period or special timing is required
   • Monitor for development of vaccine-related rash

2. If vaccine recipient develops a rash:

   • Avoid direct contact with the immunocompromised person until the rash resolves
   • No need for VZIG prophylaxis if accidental exposure occurs

3. For the immunocompromised person themselves:

   • Do NOT administer varicella vaccine (with limited exceptions for certain HIV patients)
   • Consider vaccination before starting immunosuppressive therapy when possible

By following these guidelines, the risk of wild-type varicella infection in immunocompromised individuals can be significantly reduced while maintaining a favorable safety profile.