Neither of these things are guaranteed to happen if you get the flu vaccine when you are sick, but they are possibilities. If you have just a mild illness, there is no reason to wait to get vaccinated.
Early in the day, let roast stand at room temperature at least 1 hour before cooking. Preheat oven to 375 degrees. Rub meat ... the outside and rare in the middle. Meat will be very brown ... stand at room temperature for at least one hour.
Cook the roast at 325 until the internal temperature reaches about 145 degrees. Remove from the oven, and let set with a tent of aluminum foil over it (loose piece of foil). The roast will continue to cook, and you will get a medium-rare roast that is tender. Source(s):