11.   And on Friday, Pfizer delivered a possibly crippling blow, saying that it was pulling out of a partnership to develop the vaccine.

12.   And once a vaccine is successfully developed against one strain, he said, it should be relatively easy to adapt it to fight other strains of the virus.

13.   And the National Institutes of Health, the CDC and the WHO are working together on plans to develop a vaccine to prevent TB.

14.   And the findings raise a theoretical possibility of developing a vaccine to prevent myeloma, the authors said.

15.   Big vaccine makers like Wyeth have also forged ahead with yearslong efforts to develop vaccines like Prevnar.

16.   A few years after Salk developed his vaccine, Dr. Albert Sabin produced an oral vaccine which was easier to administer and which eventually replaced the Salk serum.

17.   A new anthrax vaccine is being developed by the DynPort Vaccine Co. under contract to the Department of Defense.

18.   A previous attempt to develop a vaccine against RSV ended in disaster, with vaccinated children developing very serious and even fatal disease.

19.   But if a company developed a vaccine against the African type, it would run the risk of marketing a product that no nation could afford.

20.   But McKinnell said companies would be willing to make fixed-price bids on contracts to develop vaccines for rare diseases like Ebola virus.