Read the sentence again, and while you're at it maybe try finishing the article....

I have an appointment for my second shot in exactly three weeks. They set it up immediately after your first shot, before you leave. So part of the relief was *also* the certainty that the first shot gives you a fixed appointment for the second one. The point of this article was to focus on the mental and emotional relief you get just from getting that first shot.

From one scholar to another: Maybe you should pay a little more attention to words before trying to blast someone online...