The US Senate is coming close to reaching agreement on a pared-down $10bn emergency aid package for Covid response, amid anger that the deal looks likely to ditch most funding for critical global vaccine efforts.

Senate leaders were indicating to reporters on Friday that a deal was within reach, with a possible vote over the next week. But the package is a pale reflection of the original White House request for $22bn, cutting deep into even the most recent proposal set at $15.6bn.

A large slice of the savings will probably be made at the expense of efforts to support vaccination drives around the world. The Biden administration had asked for $5bn, but as final talks continued it appeared that the amount for global aid could be slashed to as little as $1bn.

Leading Democrats have expressed dismay at the reduction in planned global vaccine efforts. Nancy Pelosi, speaker of the House, called the latest proposal “shameful”, pointing out that low vaccination rates in parts of the world run the risk of new Covid variants arising.

“We have said, we have pronounced, everyone knows: none of us is safe, unless all of us are safe,” Pelosi said.

Chris Coons, Democratic senator from Delaware, also decried the global cuts as shortsighted. “There are 2.5 billion people unvaccinated in the world, and that is an ongoing daily risk to the United states,” he told the Washington Post.

Some top Republicans also expressed unease. Mitch McConnell, the minority leader in the Senate, told Punchbowl News that it would be “terribly unfortunate” if international vaccine support were removed from the final deal.

Much of the funding currently earmarked in the proposals would go towards domestic treatments for people with Covid-19 in order to help outcomes and to reduce stress on hospitals. Another slice of the money would go towards research on new vaccines and treatments.

One concern about the reduction in funds is that the US could become less prepared in the event of a renewed surge of infection. Average cases have plateaued in recent days, though there is still concern about BA 2, the new contagious Omicron subvariant that is now dominant in the US and that has seen a spike in Europe and the UK.

The United Nations has repeatedly warned about low vaccination rates in parts of the world. Earlier this month the UN high commissioner for human rights, Michelle Bachelet, lamented the “grim reality” that only 13% of people in low-income countries were vaccinated compared with almost 79% in high-income countries.

“The result is more than 60,000 deaths per week, along with an increased risk of the emergence of new variants,” she said.