I'm currently trying to develop an estimation of the effectiveness of pursuing a career in mitigating Global Catastrophic Biological Risks (GCBRs). As part of the EA Global in-depth reading group, I read "Existential Risk and Cost-Effective Biosecurity" by Piers Millett and Andrew Snyder-Beattie (2017). The authors' estimates of the probability of GCBRs over the next century seemed very low (from 1.6 x 10^-6 to 0.02 over the next century, depending on which of the three methodologies used by the authors gives a better estimate).
I could not seem to find any other sources that try to rigorously estimate the risks of GCBRs. Would forum users would be able to point me to some, please?  Thanks all in advance!
 Even with the highest estimate of 0.02 of GCB events per century, longtermist assumptions (of 10^16 potential lives lost, as indicated by the author) are needed for GCBR-mitigation to be more cost-effective than Givewell's top charities (taken as $4500/life saved). I would prefer not to make longtermist assumptions, in line with Neel Nanda's (2021) call to "Simplify EAPitches to 'Holy Shit, X-Risk'".
 With this input, I hope to write a more extensive post clarifying the priority areas in mitigating GCBRs (possibly pointing to risks of GCBRs from emerging biotech that enable bioterrorism as a priority area; in contrast with a focus on state-led biowarfare). If we are focusing on emerging biotech rather than existing biotech, estimates of whether these technologies would even materialise would be an important consideration as well.
Hey, this is a great question with good context for potential answers too. If you don’t get any substantive responses here, I’d suggest posting as a question on the frontpage — the shortforms really don’t get much visibility.