Wrong.
First of all, we did it with Ebola, even though that is more lethal but about the same infectiousness.
Second is that General Washington did it with smallpox in 1777.
By "innoculation", they mean deliberate infection, known as variolation.
Vaccines did not exist yet for more than another 20 years.
www.nps.gov
{...
Smallpox impacted the Continental Army severely during the Revolutionary War, so much so that
George Washington mandated inoculation for all Continental soldiers in 1777. Just fifty-six years earlier, in 1721, Bostonian doctors and clergy introduced the procedure to the American colonies.
...}
Any epidemic can easily be ended in about a month.
It just depends on if people are willing to do what it takes.