Code for https://analyticgarden.blogspot.com/2022/01/breakthroughs.html and https://analyticgarden.blogspot.com/2022/02/breakthroughs-again.html.
The blog post shows plots generated from CDC data fround at https://data.cdc.gov/Public-Health-Surveillance/Rates-of-COVID-19-Cases-or-Deaths-by-Age-Group-and/3rge-nu2a. See the blog post for details.