Pinned straw:
Additional notes – I asked my assistant for a simple non-scientific explanation of how Galidesivir works and what makes it different from non-broad based treatments. I think it did a good job and others will find useful:
Galidesivir is a man‑made chemical that closely resembles one of the basic “building blocks” that viruses use to copy their genetic material. When a virus is trying to multiply, it uses a special copying machine. Galidesivir sneaks into this process and jams that machine so the virus cannot keep making new copies of itself.
Because many dangerous viruses – including Marburg, Ebola and Sudan virus – all use a very similar copying machine, the same drug can interfere with many of them. That is why Galidesivir is called “broad spectrum”: it is designed to work against a wide range of related viruses, rather than being custom‑built for just one strain.
By contrast, most existing Ebola treatments and vaccines are like very specific keys made to fit one particular lock on the virus surface. If the virus surface changes enough – for example, a different Ebola species such as Bundibugyo – those keys no longer fit. Galidesivir targets the internal copying machinery instead, which is more similar across these viruses, so in principle it can still work even when the outside of the virus is different.