Dr Oz? That guy is the Captain Kangaroo of medicine.
The word you are looking for is not Virulent - it’s infectious or transmissible.
Virulent means it would have “worse or more deadly” action.
The higher deaths in NY area have been rightly explained and attributed to NY areas higher population density, and improper government policies (like for example sending confirmed COVID patients into nursing homes that did not have any COVID in them before). Also, decreasing the number of subway cars and buses (keeping the fewer riders still crammed together).
No, the correct word is virulence. The infectivity is not yet known due to lack of antibody testing data. Dr. Oz, in his own words on the radio, proposed the idea that the European-spread virus was more virulent (deadly) than the one coming directly from Wuhan. It was a fact-based musing, and will require post-epidemic study using factual numbers, if we can get them.
I have never cared much for Dr. Oz, but I have to admit he has been a steady voice of knowledge and reason during this time.