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.
Studies show that flu antiviral drugs work best for treatment when they are started within 2 days of getting sick. However, starting them later can still be helpful, especially if the sick person is at high risk of serious flu complications or is very sick from the flu. Follow instructions for taking these drugs.