“…Considerable efforts have been made over the past several decades to develop vaccines against IHN, and the main studied vaccine types include inactivated vaccines ( 7 to 10 ), attenuated live vaccines ( 11 , 12 ), subunit vaccines ( 13 ), and DNA vaccines ( 14 , 15 ). In 2005, an IHN DNA vaccine (Apex-IHN) ( 16 ) was approved in Canada, becoming the first and only IHN vaccine to be successfully marketed.…”