The reason why this is a big deal is because they figured out a way to engineer the type of cells that are hard to create that can readily fight off the virus. In some people they create them already. Here they were able to get the body to create them.

I agree it is far off from something in humans but it's a giant leap. The way I see it is like sending Laika in space before we send humans. It's significant and promising of a future where humans might have a vaccine.

Long-acting antiretroviral injection ≠ vaccine