The IgA antibodies, which have higher avidity than IgG antibodies, can readily access mucosal viral antigens and are able to provide protection against heterologous strains [20]. the second immunization, pigs were challenged with the antigenic variant Swine/MN/08 H1N1 (MN08) and the heterologous Swine/NC/10 H1N2 (NC10) influenza virus. Antibodies in serum and respiratory tract, lung lesions, […]