Yellow Fever

Key Information

• Transmission: Yellow fever (YF) virus is transmitted to humans through the bite of infected mosquitoes.
• Endemic Regions: Sub-Saharan Africa and tropical South America.
• Vaccine Availability: Only at designated Yellow Fever vaccination centres in Canada.
• Immunity: 95% to 99% seroconversion rate; presumed lifelong immunity in healthy individuals.
• Common Adverse Events: Pain, inflammation, swelling at injection site, weakness, headache, myalgia.

Recommendations for Use

• General Population: Recommended for healthy persons 9 months and older.
• Infants 6 to 8 Months: May be considered if traveling to high-risk areas.
• Older Adults (60+): Should be considered for vaccination only if travel to YF endemic areas is unavoidable.
• Laboratory Personnel: Recommended for those working with YF virus.

Booster Doses and Re-Immunization

• General Population: Booster doses not generally recommended.
• Specific Populations: One-time booster dose recommended based on individual risk factors (e.g., immunocompromised individuals, laboratory personnel).
• International Health Regulations: WHO states a single dose confers lifelong immunity, revaccination not required for international travel.

Vaccination of Specific Populations

• Pregnancy and Breastfeeding: Generally avoided; considered only if travel cannot be postponed.
• Immunocompromised Persons: Generally should not receive YF vaccine; risk assessment required.
• Travellers: Vaccination recommended for those traveling to or living in YF endemic areas; documentation required for entry into some countries.

Preparations Authorized for Use in Canada

• Authorized Vaccine: YF-VAX®
• Manufacturer: Sanofi Pasteur Limited
• Type: Live, attenuated yellow fever vaccine

Administration Practices

• Dose: 0.5 mL administered subcutaneously.
• Concurrent Administration: Can be given with other vaccines (e.g., measles, mumps, rubella, polio).

Safety and Adverse Events

• Common Adverse Events: Headache, myalgia, injection site reactions.
• Serious Adverse Events: Rare, but include YF vaccine-associated neurotropic disease (YEL-AND) and viscerotropic disease (YEL-AVD).

Storage Requirements

• Storage: Store in a refrigerator at +2°C to +8°C; use within 1 hour of reconstitution.