I believe that a 'dynamic low' is produced by The strong rise of air.
A dynamic low develops if the air flow converges in lower regions of the atmosphere and diverges in altitude while the air is kept up in the center of the low. A low pressure area is a region on the topographic map where the atmospheric pressure is lower than that surrounding locations. Low pressure systems form under areas of wind divergence that occur in the upper levels of the troposphere.
A vaccine can help keep people healthy and protect them from a certain virus. For example people in the United States get the flu shot when they get this shot the vaccine wont magically get rid of the virus but rather help them fight it off and protect them in the future if they keep up to date getting the vaccine
