1. Pfizer Worldwide Research, Development & Medical, Cambridge, MA 02139, USA.
2. Pfizer Worldwide Research, Development & Medical, Pearl River, NY 10965, USA.
3. Pfizer Worldwide Research, Development & Medical; Groton, CT 06340, USA.
4. Pfizer Worldwide Research, Development & Medical, La Jolla, CA 92121, USA.
5. Institute for Antiviral Research, Department of Animal, Dairy, and Veterinary Sciences, Utah State University; Logan, UT 84322, USA.