An antifreeze is an additive which lowers the freezing point of a water-based liquid. An antifreeze mixture is used to achieve freezing-point depression for cold environments and also achieves boiling-point elevation (anti-boil) to allow higher coolant temperature.
The strains of virus the trivalent vaccine protects against two A viruses (an H1N1 and an H3N2) and an influenza B virus. The quadrivalent vaccine adds another B virus to the vaccine which helps expand the level of protection to the recipient.
Trivalent flu vaccines include: 1  Standard-dose trivalent shots (IIV3) that are manufactured using virus grown in eggs. 2  A high-dose trivalent shot, approved for people 65 and older. 3  A recombinant trivalent shot that is egg-free, approved for people 18 years and older.