Lihui Li, a former president of the state-owned Bank of China, recently argued that in light of the epidemic China’s central bank should speed the release of its planned digital currency, which is supposed to replace physical cash. Then last week, when asked about whether cash could spread coronavirus, a spokesman from the World Health Organization apparently told the UK newspaper the Daily Telegraph that “it’s a good idea to use contactless payments” when possible. (Later, the WHO clarified that this was not actually coronavirus-specific guidance, and that it has not issued any official warnings about cash.)

But the truth is, there isn’t much evidence that quitting cash would make a difference, at least in the case of Covid-19. It would, however, have significant consequences for the many people who rely on cash for access to goods and services—and that may help explain why the WHO was so quick to walk back the line about contactless payments.

Here’s what we know: Infectious viruses, including other coronavirus varieties, can live on inanimate surfaces (pdf) including metal, paper, and plastic for hours to days. Preliminary research indicates that the novel coronavirus can survive on cardboard for a full day, and on steel and plastic for up to three days. And laboratory-based simulations have shown (pdf) that other kinds of viruses can not only live on banknotes and coins for days but also maintain their infectiousness.

But it’s not enough for the germ to survive on an inanimate surface. For virus particles on a dollar bill to infect a human, they must follow the “primary route of infection,” says Joseph Eisenberg, a professor of epidemiology at the University of Michigan. For Covid-19, it appears that people become infected by inhaling particles someone else has coughed or sneezed into the air, or by contacting a virus particle with their hand and then touching their eyes, nose, or mouth. What we don’t know, says Eisenberg, is how capable this virus is of being transmitted to humans from inanimate surfaces of any kind.

Says the US Centers for Disease Control: “It may be possible that a person can get Covid-19 by touching a surface or object that has the virus on it and then touching their own mouth, nose, or possibly their eyes, but this is not thought to be the main way the virus spreads.”

But that message hasn’t quelled fears of “virus-tainted” dollars, perhaps spurred in part by the central banks’ quarantines. According to Bloomberg, the Fed has resisted calls from industry groups to issue a statement assuring Americans that the risk of using cash is minimal.