VVM full form in medical term is a Vaccine vial monitor, which is used to determine whether the vaccine is usable or not. Sometimes it happens when the vaccine is exposed to high temperatures (cold and heat) and in that case, the vial of the vaccine should not be used. And to get to know whether a vial of vaccine is exposed to high-temperature fluctuations or not, the VVMs or Vaccine Vial Monitors are used.
In the ampoule vaccines and freeze-dried vaccines, the VVM is present at the top of the vial, and with liquid vaccine vials, you’ll see it on the side. You can easily identify a VVM on a vaccine vial. It looks like a tag, where a lighter square is present in a darker circle. Reading a VVM is pretty simple as well, when the inner square is lighter in color than the outer circle, the vaccine can be used. And when the inner circle starts to change color or gets darker, you should notify your supervisor and dispose of such vaccine vials. When the inner square isn’t darker than the outer circle, but the VVM has changed its color, the vaccine can be used only after checking the expiry date.