Mild Reactions
Yellow Fever vaccine has been associated with fever, muscle aches, and local soreness, redness or swelling at the vaccination site on the arm. These problems occur in up to 1 in 4 persons vaccinated. They usually begin soon after the vaccination, and can last for up to one week.
Severe Reactions
Severe allergic reaction to a vaccine component (about 1 person in 55,000).
Severe nervous system reaction (about 1 person in 125,000).
Life-threatening severe illness with organ failure (about 1 person in 250,000).
This risk is increased over the age of 60 ( 1in 100,000 age 60-69; 1 in 43000 age > 70)