the delta surge. i think it's much better if it turns out to be a false alarm and we did all the preparations and it turn out not to be a big deal but actually one of the things it could help with is maybe getting boosters out, for example, could help us to stem the delta surge. getting prepared is exactly the right thing for us to do at this point. >> sanjay, can you just give us kind of the long view in this? because just hearing this, i main i think like a lot of people, when i heard this news i just thought, you know, it seems like -- you know, relatively speaking, things were going in the right direction. then this thing comes along. but as we were talking about, unless everybody gets vaccinated around the world or has access to vaccines, i mean, this can just drag on for years and years and years with -- with new mutations occurring. >> yeah. i mean, you know, variants are likely to keep occurring as the virus continues to transmit. the more it transmits from person to person, the more mutation may occur but that doesn't mean they are all going to be potentially problematic mutations, either.