Figure 1. Comparison of vCJD incubation periods in wild-type mice from inoculation of brain tissue homogenates from 2 patients from Spain (son, patient 1; mother, patient 2) with vCJD and a reference patient from the United Kingdom. Results show similar incubation period ranking. Incubation periods were calculated in mice showing clinical and pathologic signs of transmissible spongiform encephalopathy disease. There was a single positive case in VM mice from patient 2. Data show mean incubation period ± SEM. vCJD, variant Creutzfeldt-Jakob disease.