Maybe they thought they were on to something, but that facility fell as did the CDC, and there's nobody left with that kind of technology. It's also entirely possible that they would've eventually run into a brick wall with their possible solution.
Jenner didn't even know if it was a virus/ microbe/ bacteria etc with all of his resources, he had been in contact with the French and if they knew this basic bit of information one would have expected them share it with him.
Speaking of which is seems inconceivable to me that with the vast resources the US government has - especially the multiple safe houses the President and his staff in the case of nuclear war that someone out there hasn't made more progress on the infection.
In the novel series World War Z the US government has transformed a aircraft carrier to the new seat of power and Hawaii is zombie free.
Yet, in the Walking Dead the whole world has gone to shit and there doesn't seem to be any organized military effort to eradicate the problem. Why?
Well WWZ takes place over a 10 year time span. The "after action" report that Max Brooks is supposedly writing for the UN is shortly after the end of major hostilites more than a decade afte the Great Panic.
I believe in the book it was not long after the start of the Great Panic and the collapse of the major cities that the US and most other functioning military authories decided to follow the Redekker Plan and simply fall back to fortified positions and regroup/rebuild. It was several years after the Panic that the UN started to coordinate the global offensive.
Season 3 of the Walking Dead takes place about 1 year after their version of the Great Panic. Remeber in Season 2 we did see some flashbacks to the early military attempts to keep the Zs at bay. Remember, Atlanta was firebombed (thoug, oddly it showed no signs of it while they were in the city).
Even assuming that TWD followed WWZ's timeliine, we would still be a couple of years away from any organized military offensive. Plus, even in the book, there were communities and people that went years without seeing ANY efforts from armed forces.