The second priority is to identify how the person could have contracted COVID-19 in the first place, and we have to do those two things in parallel. We can't do it neatly, one after the other. The case investigation process looks at both of those things, because it's important that we understand how the person got it, first of all, to identify what the risk associated with that is, and then, second of all, to try and make sure that a similar group of cases can't happen again in the future. 