Yellow fever virus
From IDWiki
Background
Microbiology
- RNA virus and member of the Flaviviridae family
Epidemiology
- Worldwide, about 200,000 cases and 30,000 deaths annually
Clinical Manifestations
- Spectrum of illness from asymptomatic to fatal
- Acute illness starts with fever, chills, headache, backache, myalgias, arthralgias, nausea, vomiting, photophobia, mild jaundice, and epigastric pain
- After the acute illness subsides, about 85% of infections are resolved, and 15% progress
- In those who progress, a brief remission of hours to days is followed by return of symptoms with progression to renal failure, hemorrhage, and thrombocytopenia
Vaccine-Related Disease
- Yellow fever vaccine-associated neurotropic disease, which includes meningoencephalitis, Guillain-Barré syndrome, and acute bulbar palsy
- Yellow fever vaccine-associated viscerotropic disease, which causes multi-organ failure similar to wildtype virus
| YEL-AND | YEL-AVD | |
|---|---|---|
| Incubation period | 7 to 21 days | 2 to 5 days |
| Rate | 0.8 per 100,000 doses | 1 per 100,000 doses |
| Risk factors | age <6 months
age >60-70 years |
age >60 years
thymus disease |
| Prognosis | full recovery | 65% mortality |
Management
- Supportive care
Prevention
- A live attenuated vaccine strain is available, with a single dose provided at least decades of and possibly life-long immunity
- Antibodies develop within 28 days
- Contraindications
- Allergy to any component of the vaccine
- Immunocompromised state, including HIV with CD4 <200 or <15%, B-cell deficiency (except isolated IgA deficiency, IgG subclass deficiency, and specific antibody deficiency), and combined B- and T-cell deficiency
- Infants less than 6 to 9 months of age, due to the high risk of neurotropic disease following immunization
- People age 60 years and older, due to the high risk of adverse events following immunization
- Booster doses may stll be given, if indicated
- Pregnancy and breastfeeding
- Thymus disease, including thymoma, thymectomy, and myasthenia gravis, given the high risk of viscerotropic disease
- Moderate or severe acute illness
- Booster doses
- No longer routinely indicated
- May be indicated if the original dose was given when the recipient was unlikely to mount a full immune response
- Vaccinated during pregnancy, while on immunosuppressants, or other immunocompromise like HIV
- One-time booster for most, and booster every 10 years for HIV
- Hematopoietic stem cell transplant since last vaccination
- One-time full dose
- Last dose was fractional, given improperly, undocumented, or underdocumented
- One-time full dose
- Vaccinated during pregnancy, while on immunosuppressants, or other immunocompromise like HIV
- May be indicated for individuals at particularly high risk of exposure
- Travel to an area experiencing an outbreak
- Frequent or prolonged travel to areas with high endemicity, particularly West Africa
- One-time booster if 10 or more years since primary vaccination
- May be indicated for individuals with regular and ongoing exposure
- Laboratory workers working on yellow fever virus
- Booster every 10 years unless antibody titres confirm ongoing immunity
- Vaccination can cause YF vaccine-associated neurotropic disease and YF vaccine-associated viscerotropic disease
