Heterologous Antibody Responses Conferred by A(H3N2) Variant and Seasonal Influenza Vaccination Against Newly Emerged 2016–2018 A(H3N2) Variant Viruses in Healthy Persons

Swine origin A(H3N2) variant [A(H3N2)v] viruses continue to evolve and remain a public health threat. Recent outbreaks in humans in 2016-2018 were caused by a newly emerged A(H3N2)v cluster 2010.1, which are genetically and antigenically distinct from the previously predominant cluster IV. To address the public health risk, we evaluated the levels of heterologous cross-reactive antibodies to A(H3N2)v cluster 2010.1 viruses induced from an...