title: Influenza A/H1N1 antibody after heterologous vaccination.
mesh_terms: D000328:Adult; D000367:Age Factors; D000914:Antibodies, Viral / Q000032:analysis; D001530:Belgium; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D009980:Influenza A virus / Q000276:immunology; D007252:Influenza Vaccines; D007251:Influenza, Human / Q000517:prevention & control*; D008875:Middle Aged; D014611:Vaccination
chemical_list: D000914:Antibodies, Viral; D007252:Influenza Vaccines