Insights into immune evasion of human metapneumovirus: novel 180- and 111-nucleotide duplications within viral G gene throughout 2014-2017 seasons in Barcelona, Spain

•HMPV has a prevalence of 3%, affecting equally children and adults.•180- and 111-nucleotide duplications emerged, increasing in prevalence over seasons.•G proteins w/ duplications protruded more from the membrane than w/o duplication.•Viruses w/ duplications were more associated to LRTI in adults than w/o duplication.•These facts suggest these duplications might enhance an immune evasion mechanism