Thanks Red Badger. The truth is, 100s of 1000s die of the flu, every year, but since 1918 the population of the Earth has risen six- or sevenfold, and in the US enough people get the vaccination that relatively few (between 5 and 20 percent, per the NIH, with 200K hospitalized and 36K dying, mostly over 65 or very young children) contract flu. Those who do are likely to get it diagnosed, and there are OTC meds, clean water, and warm beds at home, doctors, hospitals, basically the best health care on Earth, so the US death toll is pretty small (by percentage; US is about 5% of the Earth's population, has somewhere between 1 and 2 percent of influenza deaths).
Gina Kolata, author of "Flu" -- her keyword, newest to oldest:
Didn’t Rupert Holmes write the Gina Kolata song?
Fifty posts and no mention of Vitimin D3 as a preventative for flu
Large doses of vitamin D3 have a definite effect on eliminating fatal respiratory problems related to flu