This is a highly specific response that involves specialised cells called lymphocytes and takes place in the lymphatic system. There are two paths of the adaptive immune response: the humoral response ...

Humoral response was defined as either a fourfold or more rise in titre, or a rise from a non-protective baseline level of <1/40 to ⩾1/40 in HI antibodies 4 weeks after vaccination.12,13 Geometric ...