Influenza virus may be detected by various molecular assays including real time polymerase chain reaction (rt-PCR). In the rt-PCR procedure, RNA is isolated from experimental samples. The viral RNA or DNA is amplified using PCR. During PCR, primers specific to the influenza are used so that PCR is not carried out unless the DNA content is specific to what you target.
Each seasonal flu vaccine contains antigens representing three (trivalent vaccine) or four (quadrivalent vaccine) influenza virus strains: one influenza type A subtype H1N1 virus strain, one influenza type A subtype H3N2 virus strain, and either one or two influenza type B virus strains. When trivalent vaccines are used, there is a possibility of a mismatch between circulating and vaccine B strains. That is, the selected B strain may be of either Yamagata or Victoria lineage. A quadrivalent vaccine may include both B strains.Share