Here is up-to-the-minute information regarding vaccines in Arlington County.
A member here is living overseas, and has two elderly parents (90 and 81) living in Arlington. I was going to take them to get their vaccines, but did some research first - here's what I found:
At Walter Reed Community Center, they were giving vaccinations (with long lines) 1-2 weeks ago. I just went there and asked how to go about doing this, and a kindly, older gentleman at the front desk gave me a very long, non-answer. The upshot is that "they" (perhaps the Community Center, perhaps the entire county) ar