I don't have Photoshop, but there's an ancient open source project called refocus-it (for iterative refocus), which uses some of the same techniques as Photoshop's new-in-CS6 deblur feature. This should give better results than sharpening with unsharp mask or a high-pass filter. Below, I chose (after some experimentation) a radius of 3.1 and (since the image is very noisy) a noise reduction level of 4000, and 100 iterations, giving this result:

There are a few weird flat artifacts on the faces, and some clear jaggies around the edge of the flag, but this was a really quick pass. Plus, I'd be surprised if the decades-newer technology in Photoshop can't do a better job. In any case, I think it's at least better than the sharpened result overall. If you don't mind spending a lot of time at it, I might try one approach in one layer and the other in a different layer, and selectively (and softly) erase so that you get the best result in each area of the photo.

You can get similar results with the "Sharpen (Richardson-Lucy)" filter in G'MIC. Here's the sample photo run through that with 100 iterations:

And again, some by-hand touch-up and blending will make it look nicer. It's not ideal, but decent for social media sharing and just fine for small prints.