Seeing plenty of cheap fares on US carriers from
BOS-PVG and PHL-PEK/PVG for 400$ or less.
Open availability through at the least March of 2020.
EWR-PVG Nonstop for 577$ with UA including 2 free bags in NOV.
Please note that if you are flying to China as a destination and not transiting to a 3rd country you need a VISA.
As a side note In 2016 i missed my flight to PEK on AA in J due to the airline not being familiar with China's Visa Free Transit (so in the future i would arrive with ample time)