. Author manuscript; available in PMC: 2015 Jan 29.
Published in final edited form as: J Gen Virol. 2013 Nov 13;95(0 2):413–422. doi: 10.1099/vir.0.059188-0
© 2014 The Authors. Published by Society for General Microbiology.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/)