41.   Instead, the AIDS vaccines work to hold HIV infection in check.

42.   The monkeys are more closely related to humans than any other species in which an Ebola vaccine has worked.

43.   The nasal vaccine works by stimulating the immune system through the same nose tissue where the flu virus attacks.

44.   The polio vaccine works by spurring the immune system to make protective antibodies.

45.   Why the vaccine works in women but not men is unclear, although the researchers said it probably has something to do with differences in sexual anatomy.

46.   While researchers say the results are promising, they want to find out if the vaccine can work earlier in the progression of the disease.