Alan was looking after his big brother during daylight while the human Houstons thought Dwight was dead. At the time, Dwight didn't know that there were vampiric Houstons (like Ford). This lasted about six months, Dwight getting stronger all the time. Then the vampire who changed Dwight came back. Alan, the poor thing tried to protect his brother by going after the vampire. He got severely injured. Dwight went into a fit of rage and fought the vampire back, and drew it away, but when he came back, Alan was dying. So he changed him-- Before Ford finally arrived to where Dwight was, killed the vampire off and then realized he was too late to stop Dwight.
All Vampires have the power to hear thoughts and send psychic signals to other vampires. If they're strong enough, their messages can cross continents.
Alan is currently under Ford's protection. He'll be sent to Dalton eventually.