Alot of researchers now think that many of the young, previously healthy victims from 1918 had contracted secondary staph infections from the hospital wards, another thing that could have been taken care of, in many cases, with antibiotics.
Unfortunately that is not relevant to this flu. Additionally we have MRSA now which is not easily treated with antibiotics.
Even good old Staph Aureus can be a difficult bug, and anything systemic is high risk.
Treating sepsis is just not as simple as using IV bug juice.