4 definitions of HPR. Definition of HPR in Business & Finance. What does HPR stand for?
According to the Centers for Disease Control (CDC), you should allow two weeks after getting a flu shot to develop protection against the flu. That's because after vaccination, the body has to work for a while to create the protective antibodies to the flu virus. Bear in mind, though, that there's a lot of variation in how fast different people's immune systems work.
I want to know the prece. It depends: It depends on when in your cycle you started the shot. If you started on the first day of bleeding, it's effective right away. If later in your cycle, it typically takes 7 days to take effect, so use back up prior to then. It also may depend on when you last had sex, and what you used for protection.