Why are we rushing to create a vaccine if we already have Hydroxychloroquine?

Here's a twist: my friend was just exposed to someone who has CoVid(person did not know at the time). He socially distanced, but following his visit with her, she tested positive.

Now consider this: my friend has rheumatoid arthritis, and guess what they prescribe for it? You guessed it. So he is waiting for the results of his test.