Immunization in transplant patients

An update on immunizations before and after transplantation in the pediatric solid organ transplant recipient

Vaccination offers a unique opportunity to decrease the burden of infectious complications following solid organ transplantation. In this paper we review the current guidelines for routine immunizations before and after solid organ transplantation, including the recent updates and changes to recommendations for certain vaccines. We also address the issue of waning immunity in solid organ transplant recipients and discuss the current data on vaccinating this patient population with live vaccines after transplantation.

Demand for evaluation of vaccination antibody titers in children considered for renal transplantation

Vaccinations are recommended for achieving protection against vaccine-preventable infections in solid-organ transplant recipients. In order to evaluate the protection at the time of renal transplantation, the antibody titers against measles, mumps, rubella, varicella, hepatitis B, diphtheria, and tetanus were determined in 35 children one month prior to transplantation. Only 26% of patients on dialysis listed for transplantation showed protective antibodies against all tested pathogens. Particularly, low protection was found for hepatitis B. Children younger than four yr showed significantly lower protective antibody titers compared with older children for almost all vaccines. Children who completed vaccination in the last six months to six yr prior to renal transplantation showed higher rates of protective antibody titers against all pathogens compared with children who had vaccination more than six yr before transplantation. Preventive strategies in children with chronic renal failure include repeated measurements of serum antibodies and appropriate revaccination if titers decline. Our results underline the demand for continuous surveillance of specific antibody titers against vaccine-preventable diseases in the risk group of renal transplant recipients.

Safety of live-virus vaccines for children with immune deficiency

PURPOSE

Conduct an integrative literature review to evaluate the safety and effectiveness of live-virus vaccines, namely, the measles, mumps, rubella, and varicella vaccines, in children who are immune compromised by exogenous medication either posttransplant or while undergoing maintenance chemotherapy for leukemia.

DATA SOURCES

Medline, MedlinePlus, EBSCO, PubMed, MD Consult, CINAHL, Clinical Pharmacology, ERIC, Biomedical Reference Collection-Basic, Health Source-Consumer Edition, Health Source-Nursing/Academic Edition, Ovid, CANCERLIT, and the Cochrane Library Online.

CONCLUSIONS

Because measles infection has a low incidence rate in the United States, it may be advisable not to vaccinate children who are immunocompromised and risk side effects of the vaccine. In contrast to measles infection, varicella has a higher incidence rate and poses a more imminent threat to those who are immunocompromised. Children who are immunosuppressed can receive the varicella vaccination; however, they should have regular titers drawn to confirm adequate protection against the disease and should receive boosters as deemed appropriate.

IMPLICATIONS FOR PRACTICE

The number of solid organ transplant recipients is steadily increasing with more than 600,000 solid organ transplantations worldwide since the first renal transplant in 1954. The steadily increasing numbers of pediatric patients surviving transplantation, coupled with increased life expectancy, accelerate the need for nurse practitioners to understand the management of these delicate patients following release from the transplant unit.

Vaccines for viral diseases with dermatologic manifestations

Vaccines against infectious diseases have been available since the 1800s, when an immunization strategy against smallpox developed by Jenner gained wide acceptance. Until recently, the only vaccination strategies available involved the use of protein-based, whole killed, and attenuated live virus vaccines. These strategies have led to the development of effective vaccines against a variety of diseases with primary or prominent cutaneous manifestations. Effective and safe vaccines now used worldwide include those directed against measles and rubella (now commonly used together with a mumps vaccine as the trivalent MMR), chickenpox, and hepatitis B. The eradication of naturally occurring smallpox remains one of the greatest successes in the history of modern medicine, but stockpiles of live smallpox exist in the United States and Russia. Renewed interest in the smallpox vaccine reflects concerns about a possible bioterrorist threat using this virus. Yellow fever is a hemorrhagic virus endemic to tropical areas of South America and Africa. An effective vaccine for this virus has existed since 1937, and it is used widely in endemic areas of South America, and to a lesser extent in Africa. This vaccine is recommended once every 10 years for people who are traveling to endemic areas. Advances in immunology have led to a greater understanding of immune system function in viral diseases. Progress in genetics and molecular biology has allowed researchers to design vaccines with novel mechanisms of action (eg, DNA, vector, and VLP vaccines). Vaccines have also been designed to specifically target particular viral components, allowing for stimulation of various arms of the immune system as desired. Ongoing research shows promise in prophylactic and therapeutic vaccination for viral infections with cutaneous manifestations. Further studies are necessary before vaccines for HSV, HPV, and HIV become commercially available.