1918 Pandemic influenza was most probably swine influenza spread by the Rockefeller Institute for Medical Research and its experimental bacterial meningococcal vaccine.

Could be…

Cover up?

Dr. Frederick Lamont Gates was son of Frederick Taylor Gates the principal business and philanthropic advisor to the major oil industrialist John D. Rockefeller.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2118275/

https://academic.oup.com/aje/article/187/12/2498/5059949

https://www.historyofvaccines.org/content/antitoxin-production-united-states

https://www.lewrockwell.com/2020/03/no_author/did-a-vaccine-experiment-on-u-s-soldiers-cause-the-spanish-flu/

https://en.wikipedia.org/wiki/Frederick_Taylor_Gates

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2126288/pdf/449.pdf