The influenza vaccine is unusual in that most years a different vaccine is made. Because strains of influenza virus that circulate in the community can differ from one season to the next, the vaccine must change to best protect against those different strains.
In VMware, switches are used to establish a connection between the virtual network and the physical network. With ESX and ESXi, two different kinds of switches can be used: standard switches and distributed switches.
An SD card stores data, while a SIM card can store data, be changed between different phones, and can change cell phone carriers with it.