what the advisory committee to the cdc, the questions they were sort of asking, put this together to sort of lay it out in terms of how they would look at this. is the vaccine effectiveness waning over time? is the vaccine effectiveness reduced specifically because of the delta variant? does the data vary by subpopulation? again, elderly, very elderly, compared to younger. i'm 51. should i have -- be getting the booster the same as my parents who are in their late 70s? our booster dose of covid-19 safe of immuno genetic? it's not unsafe to get a third shot, but just how much more protection does it offer the three of us that are talking here versus people who are, you know, quite elderly at greater risk? i think that's some of the data that i would want to see. in israel, for example, some of the data they first released were primarily in patients who were on hemodialysis, kidney patients. that's a different subgroup.