Why is there such a disparity between the coronavirus numbers in New York and California? California locked down only two or three days before New York, so that most likely is not the reason. Normally, there were thousands of people travelling back and forth between China and California everyday, until travel was stopped at the end of January. In November and December, 2019 it was reported that California experienced an early outbreak of the "flu". Maybe it wasn't the flu, but rather coronavirus. If it was coronavirus and not the flu, could herd immunity be the real reason why California's numbers are now so much lower than New York's? Need to do random testing of California residents and see how many test positive for coronavirus antibodies.