1. Department of Animal Health and Well-Being, University of Bari, Valenzano, Bari, Italy
2. Biologics—Clinical Research, Merck and Co., Inc., Blue Bell, Pennsylvania
3. Regional Laboratory of Virology, Baranya County Institute, State Public Health Service, Pécs, Hungary
4. Department of Hygiene and Microbiology, University of Palermo, Palermo, Italy
5. Istituto Zooprofilattico Sperimentale di Lombardia/Emilia Romagna, Brescia, Italy
6. Istituto Zooprofilattico Sperimentale di Umbria/Marche, Perugia, Italy