This has been common knowledge for at least six months, I am surprised that this author from the Scientific American did not know this. I guess if you're only reading White House press releases, this is what happens.
I think it's worth pointing out that this is just an opinion column. I wish HN had a tag or something for opinion pieces since they're so often mistaken for normal news articles (not to say you made that mistake, SQL2219).
I am just very surprised by the theme of the article. How is it that this author did not know this basic fact. I saw a video of the President speak about 2 weeks ago, and he said that if you're vaccinated you can't catch the virus. How is it that the President is saying this, when it is clearly not true. No one calls him out on it, not even Fox News.
Obviously you were not truly vaccinated when you got COVID-19...
Joking aside, this is very bad communication that has caused a lot of trouble as it creates a very easy to attack straw man for anti-vaxxers.