There is no reason why the U.S. can't get back to a relative normal without a vaccine. Canada, Taiwan and Germany have done relatively well even without imposing a draconian lockdown like China did. Also, even without vaccines and modern medicine, the U.S. was able to overcome the Spanish Flu in in the early 1900s through social distancing and masks. Of course, when you have a President who is only focused on his own safety, then hundreds of thousands of people will die despite the advances in medicine since the early 1900s.
https://www.vox.com/policy-and-politics/2020/3/24/21188121/coronavirus-covid-19-social-distancing-1918-spanish-flu
Over the next few weeks, at least, Americans are being asked to stay home. Schools and restaurants are closing down. Public events and larger gatherings are getting canceled, if not banned. People are advised to not even have friends over. All of this amounts to a huge disruption in American life.
But its not the first time the US has done this.
Back in 1918, a strain of influenza colloquially called the Spanish flu caused the worst pandemic in centuries, killing as many as 100 million people. In the US, about 675,000 people died.
In response, states and cities across the country told people to do what we now know as social distancing. Schools, restaurants, and businesses were closed. Public gatherings were banned. People were told to isolate and quarantine. In some places, this lasted for months.
It worked. Things didnt go perfectly far from it, as some cities fared much worse than others, and people didnt always obey what experts and officials were telling them. But studies show that the social distancing efforts helped slow the spread of the 1918 flu and reduce the mortality rate overall.