One really smart thing I did after feeling completely zapped from my recent booster shot was:
Eat very little food that day (under 500 calories; just a half of an apple and a Perfect Bar), and go to sleep at 5:30 PM until 6:00 AM the next morning.
I woke up completely refreshed.
If you give your body half a chance, it will heal itself.
If you give it more than chance, you’ll thrive.
Matt Fried 