evidence: Although he deferred to Swedish health authorities’ designation of Stockholm as an affected area, Judge Dooling carefully reviewed the actions of the federal Public Health Service, which ordered Siegel’s quarantine upon her return to the USA. In upholding the quarantine order, Dooling pointed to the importance of an individualized risk assessment, "taking into account previous vaccinations and the possibilities of her exposure to infection."59 Siegel was initially asked to present a certificate of vaccination against smallpox, but she had failed to produce detectable antibodies following a series of vaccination attempts and could not be certified as successfully vaccinated. Dooling noted that federal health officials had not detailed Siegel’s husband, who apparently had been successfully vaccinated prior to the trip to Stockholm.60 The judge also emphasized the need to adopt less restrictive alternatives, where available. He urged "caution[] against light use of isolation," which "is not to be substituted for surveillance unless the health authority considers the risk of transmission of the infection by the suspect to be exceptionally serious."61