31.   Like oral polio vaccines, the nose-spray flu vaccine is made of live but weakened flu viruses, Piedra said.

32.   Meanwhile, a Chinese health official was quoted as saying that no cases of the bird flu virus have so far been found in the southern Guangdong province.

33.   Participants will also discuss a Gallup poll on American attitudes regarding the flu virus that is scheduled to be released Thursday.

34.   Plain soap tears off the outer coating of flu viruses, rendering them inert.

35.   Scientists think this often occurs when a flu virus from a bird and one from a human simultaneously infect a pig.

36.   So, investigators thought, maybe the three basic amino acids were a clue to lethality, and maybe they were a feature of the Spanish flu virus.

37.   Sprayed into the nose by a syringe, the viruses stimulate production of flu-fighting antibodies in the nose and throat, where the flu virus settles first.

38.   The change allows the virus to grow outside the lungs and the intestines, where bird flu viruses are usually contained, and turns the virus lethal for birds.

39.   The evidence uncovered by studies of the Hong Kong chicken flu virus, Webster contends, are much more compelling.

40.   The drug primarily works on cells in the lungs, the primary infection site for the flu virus.