There is a subway in New Jersey. It’s called the PATH train. There are several lines. One starts at 33rd St in Manhattan and goes to Hoboken. Another starts at 33rd St and goes to Newark.
There is also a World Trade Center line that starts at where the World Trade Center stood and goes to Newark.
There are three stops in Jersey City and Hoboken that are underground. The trains go above ground at Journal Square on the west side of Jersey City.
There are many commuter trains from New York to New Jersey that are also probably carriers of the Wuhan virus. These go to all the fancier commuter bedroom communities.
Then there are lots of commuter bus lines from New Jersey into New York City. They are usually packed with people. Those buses stop at Port Authority Bus Terminal in midtown Manhattan.
Plus there is Amtrak that goes from New York to Newark on its way to Washington, D.C.
All these trains and buses carried the Wuhan virus into New Jersey with great efficiency.
Just like trench warfare in WW1.
Yes, I know. I live here.