ATLANTA (AP) -- Federal health officials on Wednesday said doctors should temporarily stop giving children the final booster shot of the Hib vaccine because of expected shortages caused by a recall.Normally, the government recommends children get the three-shot vaccine at age 2 months, 4 months and then a booster at 12-15 months. But doctors should defer giving that last booster for the time being, said officials at the U.S. Centers for Disease Control and Prevention said.