PBS did a documentary I happened to watch last month. It reveals that mailmen were a serious vector of transmission, even when quarantines were put in place. Medicine's main disadvantage was not understanding that it was viral and airborne, so that quarantines could be more effective. Doctors were looking for a bacterial cause up to the end of the pandemic. <a href="https://www.youtube.com/watch?v=l0juBE-ra3A" rel="nofollow">https://www.youtube.com/watch?v=l0juBE-ra3A</a>
Currently there is concern that the new form of the H7N9 virus in China could morph into a form as lethal as the 1918 Spanish flu which killed up to five percent of world's population. Forewarned is forearmed. But it seems:<p><i>China Has Withheld Samples of a Dangerous Flu Virus</i><p><a href="https://www.nytimes.com/2018/08/27/health/china-flu-virus-samples.html" rel="nofollow">https://www.nytimes.com/2018/08/27/health/china-flu-virus-sa...</a><p>so possible development of vaccines has been hampered.
The article prominently cites the fact that the 20-40 yr old population had not been exposed to H1N1 and thus their immune system was not primed to fight it.<p>I wonder, then, if we are better equipped today because of increased globalization as well as widespread use of flu vaccines. Virus strains can fly all over the world easier than they could 100 years ago, so there is more 'mixing'. At the same time, we are getting a flu shot every year with the current batch of popular strains. By the time we reach the age of 20, we have likely been exposed to most subtypes of Influenza.