On the safety aspect, this adjuvant type of vaccine has been used in up to 40,000 people without any significant effect. With a vaccine like Prevnar, which is the pneumococcal vaccine, virtually all the trials were done in the United States and Africa. In the United States trial there were about 37,000 individuals, and Prevnar is licensed in Canada and many other countries. That's a large study. These studies take a long time to do.
The Menactra study involved only about 10,000 to 12,000 individuals. That's the meningitis vaccine. The figures we have for this type of vaccine--the H5N1, which is the mock vaccine--plus data now being generated on the H1N1 vaccine are now getting into the same ballpark on safety and efficacy as you normally see for a vaccine. So although we say we're moving forward, this is what has happened.
In Europe and the United States there are questions about not just the adjuvant but the antigen as well. In 1976, as we heard from Dr. Butler-Jones, they came out with an H1N1 vaccine--the swine flu saga--but at that time they didn't have a real pandemic.
So it's a balance as you go forward. I think the safety margin is considerable now for moving forward with these vaccines.
Paul Lucas might have a comment on that as well.