Yellow fever vaccination in organ transplanted patients: is it safe? A multicenter study

Background. Yellow fever (YF) may be very serious, with mortality reaching 50%. Live attenuated virus YF vaccine (YFV) is effective, but may present, although rare, life-threatening side effects and is contraindicated in immunocompromised patients. However, some transplant patients may inadvertently receive the vaccine. Methods. A questionnaire was sent to all associated doctors to the Brazilian Organ Transplantation Association through its website, calling for reports of organ transplanted patients who have been vaccinated against YF. Results. Twelve doctors reported 19 cases. None had important side effects. Only one had slight reaction at the site of YFV injection. Eleven patients were male. Organs received were 14 kidneys, 3 hearts, and 2 livers. Twelve patients received organs from deceased donors. Mean age at YFV was 45.6 +/- 13.6 years old (range 11-69); creatinine: 1.46 +/- 0.62 mg/dL (range 0.8-3.4); post-transplant time: 65 +/- 83.9 months (range 3-340); and time from YFV at the time of survey: 45 +/- 51 months (range 3-241). Immunosuppression varied widely with different drug combinations: azathioprine (7 patients), cyclosporine (8), deflazacort (1), mycophenolate (10), prednisone (11), sirolimus (3), and tacrolimus (4). Conclusions. YFV showed no important side effects in this cohort of solid organ transplanted patients. However, owing to the small number of studied patients, it is not possible to extend these findings to the rest of the transplanted population, assuring safety. Therefore, these data are not strong enough to safely recommend YFV in organ transplanted recipients, as severe, even life-threatening side effects may occur.