COVAX is a new mechanism. It's the biggest mass deployment of vaccines around the world that we've ever seen on this scale, so it's learning as it evolves. Now we're also seeing COVAX starting to introduce minimum shelf lives for doses being donated, so that when they land in a country, they have at least a certain amount of time left to be able to turn that vaccine into a vaccination.
Those things are changing and happening in real time, because we're learning as we go.