With the distinct possibility of pro sports resuming in empty venues, a recent poll suggests a majority of U.S. fans wouldn’t feel safe attending games anyway without a COVID-19 vaccine.

According to the Seton Hall Sports Poll, 72% of Americans said they would not feel safe attending games without a vaccine, though the number dropped to 61% among people who identified themselves as sports fans. Nearly half the respondents in the poll, which had a margin of error of plus or minus 3.6 percentage points, said they either didn’t follow sports closely or didn’t follow sports at all.

So even if fans are allowed back in stadiums or arenas, many may not come. And the financial losses in such a scenario will be significant without the revenue that comes from tickets, concessions and merchandise, among other things — even if money is flowing from lucrative media rights deals.

If the NBA and NHL have to cancel the rest of their seasons and Major League Baseball and Major League Soccer play only half their regular schedules, the losses in fan-related revenue could reach $3 billion, according to Patrick Rishe, director of the sports business program at Washington University in St. Louis.