From Science Daily:

_Scientists at the Centers for Disease Control and Prevention in Fort Collins, Colorado, USA, have developed an injection that protects against two severe diseases transmitted by tick bites: Lyme disease and Anaplasmosis.

A single dose of doxycycline given orally is only 20-30% effective at preventing these diseases in mice. The researchers found that a new formulation of doxycycline hyclate that is programmed to release the drug over a 20 day period is 100% effective._