Ric Erwin, chairman of the Fraternal Order of Real Bearded Santas, called the news "extremely disappointing," adding: "This was our greatest hope for Christmas 2020, and now it looks like it won't happen."
The plan was discussed in a 12-minute August phone call, when Caputo told Erwin that vaccines were likely to be approved and distributed by late November.
"If you and your colleagues are not essential workers, I don't know what is," Caputo said, according to a recording of the call.
Caputo said: "I'm in, Santa, if you're in."
Santas would have been asked to appear at roll-out events in as many as 35 cities, according to the discussions.
Plans for the publicity blitz began to unravel when celebrities got cold feet, fearing the vaccine campaign would become politicised.
The US$250m ($374m) publicity campaign is now under review "to determine whether the campaign serves important public health purposes".
Professional Santas' public-facing responsibilities have seen them concerned about seasonal germs before. During the 2009 flu the same professional body lobbied for members to be given flu jabs.
President Donald Trump has repeatedly told rallies, debates and press conferences that a vaccine could arrive within weeks. "We think we can start sometime in October," the President said at a White House press briefing last month.
However, officials have been more cautious, stressing a vaccine cannot be given emergency approval until it is proven safe.
Dr Robert Kadlec, a White House official leading the response to the coronavirus pandemic, said earlier this month that America could expect vaccine deliveries from January 2021. Disease forecasts predict another 100,000 Americans are likely to die of the virus between then and now.
Any vaccine roll-out faces a major public relations challenge and looks set to encounter considerable scepticism from a large share of Americans. The proportion of Americans who say they will take a vaccine has fallen sharply in recent months as fears have spread that the approval process is being rushed.
Polling by Pew Research found that in September only one-in-five said they would definitely get a Covid-19 jab, half the proportion from only four months earlier. The proportion who said they would definitely not get a jab jumped over the same period from 11 per cent to 24 per cent.