The original portfolio had seven candidates in it. When we came up with those, we looked at all of the vaccines we were aware of and distilled it down to those. On an ongoing basis, we are open to new scientific evidence about the efficacy of vaccines. When those companies come to meet with us, that is usually, or I guess always, under a confidential business approach where we can't disclose what the information is.
Mr. Scott-Douglas may be able to speak to that better.