A new study argues that city subways and buses were a “major disseminator” of the coronavirus in the Big Apple.

The paper, by MIT economics professor and physician Jeffrey Harris, points to a parallel between high ridership “and the rapid, exponential surge in infections” in the first two weeks of March — when the subways were still packed with up to 5 million riders per day — as well as between turnstile entries and virus hotspots.

“New York City’s multitentacled subway system was a major disseminator — if not the principal transmission vehicle — of coronavirus infection during the initial takeoff of the massive epidemic,” argues Harris, who works as a physician in Massachusetts.

While the study concedes that the data “cannot by itself answer question of causation,” Harris says the conditions of a typical subway car or bus match up with the current understanding of how the virus spreads.

“We know that close contact in subways is fully consistent with the spread of coronavirus, either by inhalable droplets or residual fomites left on railings, pivoted grab handles, and those smooth, metallic, vertical poles that everyone shares,” he writes.

But some experts and transit officials question the study’s findings.

Hofstra University professor of public health Anthony Santella told The Post he was “not surprised” that there was a correlation, but questioned Harris’ conclusion.

“We’re talking about early March before the restrictive public health control measures went in place,” Santella said.

“It’s certainly not solely related to the subway system. It’s because of our own behaviors and when these other measures went into place.”

MTA chairman Pat Foye echoed that point in comments to reporters Wednesday afternoon, calling the study “flawed.” He noted that Gov. Andrew Cuomo closed all non-essential businesses on March 20.

“Social density … was a result of many factors — business, restaurants, bars, Madison Square Garden, sports arenas, concerts, and the things that make New York happen,” Foye said.