Yellow Fever Vaccination – Lifelong Protection Through a Single Dose: a Narrative Review

Yellow fever, caused by a flavivirus transmitted by Aedes and Haemagogus mosquitoes, remains a major public health concern in the tropical regions of Africa and South America, affecting approximately 900 million people living in at-risk areas. The live attenuated 17D vaccine, developed by Max Theiler in the 1930s and awarded the Nobel Prize in 1951, is one of the most effective vaccines ever created, providing lifelong immunity with a single dose to over 95% of vaccinees. This comprehensive narrative review examines the immunological mechanisms behind the substantial and durable effects of the vaccine, its historical development from the Asibi strain to the current 17D substrain, current vaccination strategies, contraindications, and the risk–benefit analysis. While the vaccine has an excellent safety profile with rare serious adverse events (0.09–0.4 per 10,000 doses), the benefits far outweigh the risks for most populations, contributing to the elimination of yellow fever as a major public health threat.