The genii is out of the bottle so ending biological weapons research will never happen. If we aren't hit by a nation-state using biological warfare then we'll be hit by someone who does biochem in his garage for fun.
The best strategy is to advance the research while taking such steps as creating super-vaccines to make this type of biowarfare obsolete:
https://weather.com/en-IN/india/coronavirus/news/2021-04-21-...
But that also moves us one step closer to the "grey goo" scenario: