Don’t be. Vampires couldn’t be reflected in mirrors cause back in the day silver was used to produce them.

Now aluminum replaced silver in this regard and vampires can be seen through the mirror. 

On the other hand, while it’s now safe to say that there are no vampires in space (or at least we didn’t spot any, though technology allows for it), there’s no way to detect one on Earth. Now that is even more concerning, isn’t it? 

 You will know the vampires by their thralls.

It's a reasonable conclude they are doing quite well on earth.