What's differance between mono, di, tri and quadrivalent influenza virus vaccine?

Flu vaccine. The trivalent covers 2 a strains ; 1 b strain, the quadrivalent covers 2a and 2b strains, the second b strain causes milder disease in adults and mostly affects children. The efficacy of the quadrivalent over the trivalent vaccine has not been established in preventing disease as it just got on the market in the us. The mono and di valent vaccines are not on the market. See the cdc.Gov site 4 info.
Number of viral ant- Igens included in a vaccine. Every year influenza outbreaks involve more than one strain. Therefore, most of influenza vaccine contains 3-4 different viral antigens (tri- or quadrivalent ).