In memoriam: Stephen J Seligman, MD: Adverse reactions to the yellow fever vaccine: from epidemiological risk factors to causes and mechanisms.

In 2004, Steve first expressed his concerns regarding the safety of live flavivirus vaccines in a brief review in the I Lancet i based on the lessons learnt from the use of live attenuated YF vaccine [[8]], which had been considered one of the safest vaccines available since 1935 [[10]]. However, cases began to be reported of reactions to the vaccine termed yellow fever vaccine-associated viscerotropic disease (YEL-AVD). Moreover, a fourth patient, aged 13 years, had inherited IFNAR2 deficiency [[3], [5]], confirming the causal relationship between inborn errors of type I IFN immunity or autoantibodies against type I IFNs and adverse reactions to the YF vaccine. In 2011, Steve wrote his first letter to us: "Until 2001, yellow fever vaccine was considered the safest of the live virus vaccines. [Extracted from the article]