We may be able to scratch smallpox off the list of grave threats if our gov't follows through on their formally expressed desire to purchase Tecovirimat (ST-246).
In case you don't know already, I wanted to point you to a company called Siga Technologies. Their lead pox candidate is an antiviral (not a vaccine)called ST-246 that has proven itself to be 100% efficacious in every challenge, including monkey pox, the actual variola virus, and several emergency uses with people. It is different from vaccines in that it is effective in post-symptomatic patients where a vaccine is only works before the onset of symptoms.
Siga is currently believed to be the sole contender for a late stage BARDA award for the Strategic National Stockpile which is expected in the next few weeks to months.
The RFP for the BARDA stockpile acquisition: