I fully support basic science pursuing crazy ideas. I think this is a very interesting piece of basic science, it's just at an incredibly speculative stage that's unsuitable for clinical investment. Efficient delivery of novel proteins into a cell by genetic methods, nanoparticles, or direct transduction is -the- challenge for a lot of novel ideas. Massive effort is ongoing to find breakthroughs here. The proteins in this study face this challenge, but there are other serious issues as well: - Introducing a large amount of a foreign protein, esp. some with viral domains in them, potentially carries risk of an adverse immune reaction... especially since these proteins might quickly transduce themselves into antigen presenting cells. - Most importantly, for a viral prophylactic, it's not clear that the short persistence of these proteins in the cell really makes for an effective approach to defend against viruses. - If you administer it acutely to try and slow an ongoing infection in a stimulated immune system, I suspect the body would raise antibodies against the proteins, preventing them from being used again.

It's more "We haven't yet discovered an effective delivery method, therefore this technique is in the same place as a hundred other techniques that kill things in cell cultures."