Open AccessAntigenic drift of H 1 N 1 influenza A virus in pigs with and without passive immunity
Author(s) -
Diaz Andres,
Allerson Matthew,
Culhane Marie,
Sreevatsan Srinand,
Torremorell Montserrat
Publication year - 2013
Publication title -
influenza and other respiratory viruses
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.743
H-Index - 57
eISSN - 1750-2659
pISSN - 1750-2640
DOI - 10.1111/irv.12190
Subject(s) - antigenic drift , hemagglutinin (influenza) , immunity , biology , antigen , virology , influenza a virus , passive immunity , immune system , virus , immunology
Background The genetic and antigenic characteristics of influenza A viruses ( IAV ) within and between species change over time due to antigenic shift and drift. Although pigs are known to play a key role in the epidemiology of IAV between species, little is known about the molecular evolution of IAV hemagglutinin ( HA ) in pigs. Objectives The aim of this study was to evaluate the HA drift of an H 1 N 1 IAV after infecting weaned pigs with or without maternally derived passive immunity. Methods Three‐ to four‐week‐old piglets born either to vaccinated or unvaccinated sows were contact‐infected upon exposure with an IAV ‐infected pig. Nasal swabs were collected daily from each pig and tested for IAV by RRT‐PCR. Full‐length HA sequences were obtained directly from positive nasal swabs and compared between groups. Results Synonymous and non‐synonymous mutations were detected in pigs with and without passive immunity. Most of the non‐synonymous mutations occurred within the HA 1 region of the HA . Changes within HA 1 region were only identified in antigenic site B in pigs without passive immunity and in antigenic sites A , B , and D in pigs with passive immunity. However, there was no association between the immune status of the pig and the amino acid substitutions observed. Conclusions Overall, we demonstrated that amino acid substitutions within antigenic sites can happen in weaned pigs with or without passive immunity shortly after infection.