In a recent report from the Centers for Disease Control and Prevention (CDC), they report on a death of a woman in her 60s from a rare reaction to the yellow fever vaccine called yellow fever vaccine–associated viscerotropic disease (YEL-AVD).
According to the report, last September, a previously healthy Oregon woman reported to the hospital suffering from a variety of non-specific symptoms lasting several days.
Prior to this, the woman had received a single dose of yellow fever vaccine and typhoid vaccine before planned travel to South America.
Lab results showed a low platelet count and a few other out of range analyses.
She was admitted to the hospital with diagnoses of gastroenteritis, malaise, dyspnea, and thrombocytopenia.
The patient experienced cardiogenic shock and acute renal failure and died 3 days after admission.
Tissue and serum samples were tested at CDC for evidence of yellow fever vaccine–associated viscerotropic disease (YEL-AVD), a serious adverse reaction resulting from the uncontrolled replication of vaccine virus and characterized by multisystem organ dysfunction; 60% of reported cases are fatal. Another key finding discovered at autopsy was the thymus was diffusely enlarged, consistent with thymoma.
Yellow fever antigen was found in several organs and yellow fever vaccine viral RNA was detected in multiple organs and in a serum sample by RT-PCR. The patient also tested positive for yellow fever IgM antibody.
How common is YEL-AVD?
According to the CDC, the risk for YEL-AVD in the United States is approximately 0.4 cases per 100,000 doses of yellow fever vaccine distributed; older age and thymic disease have been associated with an increased risk for YEL-AVD–Risk increases to one case per 100,000 doses of yellow fever vaccine distributed for travelers aged ≥60 years and 2.3 cases per 100,000 doses for those aged ≥70 years.
If the patient’s thymoma was known, the vaccine would have not been recommended. There is no screening for this condition prior to receiving the vaccine.
The CDC closes the paper saying:
Although most persons have no or mild adverse events after yellow fever vaccination, the benefits of vaccination among travelers who have a limited exposure period need to be weighed against risk for adverse events. Yellow fever can range in severity from a mild febrile illness to severe disease with jaundice and hemorrhage; the case-fatality ratio for severe yellow fever disease is 20%–50%. An estimated 200,000 yellow fever cases occur worldwide annually, with approximately 87% in Africa.
The live, attenuated vaccine is recommended for persons living in or traveling to tropical South America and sub-Saharan Africa; proof of yellow fever vaccination can be required for entry into certain countries. When determining whether a patient should receive yellow fever vaccine, the patient and clinician should discuss the risk for travel-associated yellow fever disease as indicated by season, destinations and duration of travel, likelihood of exposure to mosquitoes while traveling, and vaccination status, and weigh them against risks associated with vaccination.