This week's facts include:

• Being in a good mood while getting a flu shot can boost its effectiveness. A study from the University of Notthingham found that of all the factors researchers looked at, a positive mood is the only factor that was associated with a higher level of antibody with an 8 to 14% variance.
• Boredom can be good for you! So, maybe you're one of those people who would rather staple their tongue to a piece of paper than be bored, but it turns out that boredom has many benefits (beyond not leading you to poke holes in your body).
• Smiles can be used to convey twice as many indifferent to unhappy emotions as they can happy ones.