Perspective: Swine-origin influenza: 1976 and 2009.

I am in a unique situation, having been involved in 2 major US public health events resulting from novel swine-origin influenza viruses. In 1976, I was Director of the Center for Disease Control (CDC, the name of the agency at the time) when a new influenza virus, characterized as an influenza A(H1N1) swine virus, was isolated from military recruits at Fort Dix, New Jersey. Subsequently, I led the CDC through the US response to this outbreak, which culminated in the decision to implement the swine flu vaccination program during which 45 million people were vaccinated over 10 weeks. The program was stopped after cases of Guillain-Barré Syndrome were identified following vaccination and when no spread of the virus occurred beyond Fort Dix. In 2009, as another new swine H1N1 virus was first identified and emergency response began, I was asked to be an advisor to the CDC Director in order that I might provide historical context to the novel H1N1 swine-origin outbreak and response. In this latter capacity, I have been able to observe and participate in discussions resulting in decision-making for the CDC's national response to this public health emergency as an unpaid consultant. This paper is a personal commentary on the similarities and dissimilarities of the 2 episodes.