Physics covers a wide range of phenomena, from elementary particles (such as quarks, neutrinos, and electrons) to the largest superclusters of galaxies. Included in these phenomena are the most basic objects composing all other things. Therefore, physics is sometimes called the  fundamental science .
Two types of influenza vaccines are available: 1  TIV (flu shot (injection) of trivalent (three strains; usually A/H1N1, A/H3N2, and B) inactivated (killed) vaccine) or. 2  LAIV (nasal spray (mist) of live attenuated influenza vaccine.)
These are called âtrivalentâ flu vaccines. Now, some flu vaccines protect against 4 strains. These are called âquadrivalentâ flu vaccines. After the CDC forecasts which flu strains are likely to circulate, flu vaccine manufacturers decide whether to design a flu vaccine that includes 3 strains (2 A and one B) or 4 strains (2 A and 2 B). A quadrivalent vaccine that helps protect against 2 A strains and 2 B strains may reduce the risk of being unprotected against the flu. To learn more, visit the CDC website at. http://www.cdc.gov/flu/