Copyright © 2018 American Academy of Pediatrics. From: I Red Book® 2015, 2015 Figure Legend: This transmission electron micrograph revealed the ultrastructural details of 2 avian influenza A (H5N1) virions, a type of bird flu virus, which is a subtype of avian influenza A (magnification x108,000). At this magnification, one may note the stippled appearance of the roughened surface of the proteinaceous coat encasing each virion. Courtesy of Centers for Disease Control and Prevention/Cynthia Goldsmith/Jackie Katz Date of download: 3/4/2018 Copyright © 2018 American Academy of Pediatrics. All rights reserved.