RESUMO
In pre- and post-immunisation sera from children (17-120 months-old) and adults (20-59 years-old) immunised with 2010/11 trivalent inactivated influenza vaccine, we assessed age-related patterns of sero-susceptibility and vaccine-induced cross-reactive antibodies to a representative swine H3N2 (swH3N2) and a related ancestral human H3N2 (A/Sydney/5/1997) influenza virus. Few children but a greater proportion of adults showed pre-immunisation haemagglutination inhibition titres ≥40 to either virus. Titres increased with age among children but decreased in adults. Fewer than 20% showed a four-fold rise in antibody titres to either virus following immunisation. Further investigation is warranted to guide ongoing risk assessment and response to emerging swine H3N2 viruses.
Assuntos
Anticorpos Antivirais/metabolismo , Vírus da Influenza A Subtipo H3N2/imunologia , Vacinas contra Influenza/uso terapêutico , Influenza Humana/epidemiologia , Influenza Humana/imunologia , Adulto , Sequência de Aminoácidos , Animais , Anticorpos Antivirais/biossíntese , Canadá/epidemiologia , Criança , Pré-Escolar , Reações Cruzadas/imunologia , Feminino , Humanos , Lactente , Vacinas contra Influenza/imunologia , Influenza Humana/prevenção & controle , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Suínos , Vacinas de Produtos Inativados/imunologia , Vacinas de Produtos Inativados/uso terapêutico , Adulto JovemRESUMO
We tested nasopharyngeal aspirate specimens by real-time polymerase chain reaction assays and paired serum samples by enzyme-linked immunosorbent assays. Acute human metapneumovirus infections were identified in 6 (4.1%) of 145 adult patients who presented to the emergency department for pneumonia or acute exacerbation of chronic obstructive pulmonary disease during 2 winter/spring seasons in Quebec, Canada.