Immunization in hematopoietic cell transplantation

Our manuscript discusses recommendations about immunization in patients wit h hematopoietic cell transplantation (HCT). Each of the commonly administer ed vaccines is reviewed, current knowledge summarized, and areas for additi onal studies are presented. Some general concepts emerge. Live vaccines rep resent special risks, and the risks and benefits for each vaccine must be c arefully assessed. Live poliovirus vaccine is contraindicated in all immuno compromising conditions, but an acceptable, alternative inactivated vaccine is widely available. Live measles and varicella vaccines have specific ind ications in HCT recipients, but caution should be exercised in their use. I nactivated vaccines can be generally regarded as safe in immunocompromised individuals, but immunogenicity and potential for protection vary by condit ion and severity of disease. Immunization appears to succeed best when vacc ines can be administered before anticipated immunocompromise or after immun osuppression has ended. Booster doses of vaccine may be indicated in some c ircumstances where failure of response occurs. Priming of the donor with va ccine prior to harvest al so may be an effective method to enhance the immu ne response in HCT recipients. We should also remember that household expos ure to vaccine-preventable diseases poses a risk. Strategies that encourage immunization of susceptible household contacts may partially compensate fo r poor response to vaccines in the immunodeficient patient.