I've been reading up on the Asian flu epidemic of 1957. It was similar, probably not quite as many deaths. Reading about it in old newspapers at Newspapers.com, it caused no economic crisis. The U.S. had a much better industrial policy and balanced foreign trade profile back then (IOW, we didn't rely on foreign countries to supply most of our manufactured products).
The worst part of the epidemic in the U.S. lasted through the summer and fall of 1957, but a vaccination was developed in October and cases dropped off after that. Amazing how well it was handled with little drama and a relatively quick vaccine back in 1957.
Asian Flu (1957 Influenza Pandemic)