Identification of novel human derived influenza viruses in pigs with zoonotic potential

Abstract

In 2009, a novel swine influenza A virus (IAV) emerged causing a global pandemic that highlighted the role of swine as a reservoir. To date, there is limited information about swine IAV circulating in Latin America. We identified two swine H1N2 and one divergent swine H3N2 viruses that co-circulated in Chilean swine together with the 2009 H1N1 pandemic strain (A(H1N1)pdm09). Phylogenetic analysis revealed several human-to-swine IAV introductions occurring as early as the mid-1980s, and since 2009, several introductions of the A(H1N1)pdm09 strain. Antigenic cartography confirmed that these viruses were antigenically unique and identified drifted variants within the clusters. Human sera from the Chilean general population showed an age-dependent mid to low-level antibody-mediated protection against swine H1N2 and A(H1N1)pdm09-like viruses and poor protection against the swine H3N2 virus, highlighting the zoonotic potential of this strain. Our results underscore the epidemiological importance of studying swine IAV in Latin America for epidemic and pandemic preparedness.

Cross-protection of commercial vaccines against Chilean swine influenza A virus using the guinea pig model as a surrogate

“…The strains used for the challenge were IAV-S A/swine/Chile/H1P-12/2014(H1N1), A/swine/Chile/H1A-7/2014(H1N2), A/swine/Chile/H1B-2/2014(H1N2), and A/swine/Chile/H3-2/2015(H3N2), representing genetically and antigenically different clusters previously described in Chile, named: A(H1N1)pdm09-like, Chilean H1 A, Chilean H1 B, and Chilean H3 ( 1 , 5 , 6 ). These viruses corresponded to circulating swine IAV originally derived from humans ( 5 , 7 ). The strains were grown in Madin-Darby Canine Kidney (MDCK) cells maintained at 37°C with CO 2 .…”