What Is Yellow Fever?
A serious mosquito-borne viral disease that can cause fatal haemorrhagic fever, preventable by a highly effective vaccine required for entry to many countries.
Pathogen: Yellow fever virus (YFV, Flavivirus family)
Type: Virus
Transmission
Bite of infected Aedes and Haemagogus mosquitoes. Three transmission cycles: sylvatic (jungle — monkeys to humans via forest mosquitoes), intermediate (semi-domestic, small outbreaks in Africa), and urban (large epidemics via Aedes aegypti).
Vector: Aedes aegypti (urban), Haemagogus species (jungle, Americas), various Aedes species (Africa). Daytime biters.
Symptoms
Initial phase: sudden fever, chills, headache, back pain, muscle aches, nausea, and vomiting. Most patients improve after 3-4 days. Toxic phase (15-25% of cases): high fever returns with jaundice (yellowing), abdominal pain, vomiting (sometimes with blood), bleeding from mouth/nose/eyes, kidney failure.
Incubation period: 3 – 6 days
Usually 3-6 days. Short incubation compared to many other travel-relevant diseases.
Timeline: Initial phase lasts 3-4 days. Brief remission of hours to a day. Toxic phase begins on day 4-5 in severe cases and lasts 7-10 days. Recovery or death typically within 10-14 days of onset.
Case fatality rate: Overall 3-7.5%. Among those who develop the toxic phase: 20-50%. Higher fatality in unvaccinated travellers who may lack any background immunity.
Diagnosis & Treatment
Diagnosis: Yellow fever PCR (first 5 days). IgM ELISA (from day 5). Plaque reduction neutralisation test (PRNT) for confirmation. Cross-reactivity with other flaviviruses can complicate serological diagnosis. Liver biopsy is diagnostic but rarely performed due to bleeding risk.
Treatment: No specific antiviral treatment. Supportive care: rest, fluids, paracetamol for fever. Avoid aspirin and NSAIDs due to bleeding risk. Intensive care for severe cases with organ support, blood products, and dialysis. Prevention through vaccination is paramount.
Prevention
- Yellow fever vaccination (single dose provides lifelong protection)
- DEET-based insect repellent during the day
- Wear long sleeves and light-coloured clothing
- International Certificate of Vaccination (yellow card) — required for entry to many countries
- Use screened or air-conditioned accommodation
- Avoid forested areas at dawn and dusk where possible
💉 Vaccine Available
A vaccine is available for Yellow Fever. View the Yellow Fever vaccine guide for details on schedule, cost, and availability in Australia.
Post-Exposure
There is no post-exposure prophylaxis for yellow fever. If you develop sudden high fever, jaundice, or bleeding within 2 weeks of travel to an endemic area, seek emergency medical attention immediately and inform the doctor of your travel history and yellow fever vaccination status.
Long-Term Effects
Yellow fever does not cause chronic infection. Survivors of severe disease may have prolonged convalescence but generally recover fully. Infection confers lifelong immunity. Rare cases of vaccine-associated viscerotropic disease (YEL-AVD) mimic severe yellow fever.
📋 Yellow fever is a nationally notifiable disease in Australia. No locally acquired cases occur (the vector is present in Far North Queensland but the virus is not). Cases in travellers are extremely rare due to high vaccine uptake.
Frequently Asked Questions
Which countries require a yellow fever certificate?
Many countries in Africa and South America require proof of yellow fever vaccination for entry, particularly if you are arriving from or transiting through an endemic country. Requirements vary — some countries require it for all travellers, others only for those coming from endemic areas. Check the specific entry requirements for each country on your itinerary via the WHO or Smartraveller. Your travel doctor will issue the International Certificate of Vaccination (yellow card).
Do I need a yellow fever vaccine for Southeast Asia?
Yellow fever does not exist in Asia. You do not need the vaccine for travel within Asia unless a country you are visiting requires proof of vaccination because you are arriving from or transiting through an endemic country in Africa or South America. For example, some Asian countries require the certificate if you have been in an endemic country within the preceding 6 days.
How long does the yellow fever vaccine last?
A single dose of the yellow fever vaccine provides lifelong protection. Since 2016, the WHO has stated that a booster dose is not needed. The International Certificate of Vaccination for yellow fever is now valid for the life of the vaccinated person. However, some countries may not yet have updated their regulations, so check specific entry requirements.
Is the yellow fever vaccine safe?
The yellow fever vaccine is generally safe and well-tolerated. Common side effects include mild headache, low-grade fever, and muscle aches for a few days. Rare but serious adverse events include vaccine-associated viscerotropic disease (organ failure, 0.3-0.4 per 100,000 doses) and neurotropic disease (encephalitis, 0.4-0.8 per 100,000). Risk is higher in people over 60, those with thymus disorders, and the immunocompromised. The vaccine is a live vaccine and is contraindicated in certain groups.
Where can I get the yellow fever vaccine in Australia?
The yellow fever vaccine can only be administered at designated yellow fever vaccination centres in Australia. These are typically travel medicine clinics registered with the Australian Government. Your GP cannot administer it unless they are a designated provider. A list of approved centres is available from the Department of Health. The vaccine must be given at least 10 days before entering a country that requires it.
Can I get a medical exemption from the yellow fever vaccine?
Yes. If the vaccine is contraindicated (e.g., severe egg allergy, immunosuppression, thymus disorders, pregnancy, infants under 9 months), a medical exemption letter can be issued by a designated yellow fever vaccination centre. This letter is carried in lieu of the vaccine certificate. However, some countries may not accept exemptions and may quarantine or refuse entry to unvaccinated travellers.
Do I need the yellow fever vaccine for Brazil?
Yellow fever vaccination is strongly recommended for all travellers to Brazil, particularly those visiting the Amazon basin, Minas Gerais, and rural areas. Brazil requires proof of vaccination for travellers arriving from other endemic countries. Even if not technically required for your specific itinerary, the vaccine is recommended because yellow fever is endemic in much of Brazil.
What happens if I lose my yellow card?
The International Certificate of Vaccination or Prophylaxis (ICVP, or 'yellow card') is an important travel document. If lost, contact the clinic that administered your vaccine — they should have records and can issue a replacement. If the original clinic cannot be contacted, some countries accept a letter from a doctor confirming vaccination. To avoid issues, photograph your yellow card and store a copy digitally.
Sources & References
Last updated: April 2026