LONDON (AP) — Anti-poverty organization Oxfam called Monday for governments to impose a one-time 99% tax on the world's billionaires and use the money to fund expanded production of vaccines for the poor — part of an effort to combat global inequality widened by the coronavirus pandemic.

The ranks of the super-rich have swelled during the pandemic thanks to ample financial stimulus that pumped up stocks, the group said. Meanwhile, poor countries have suffered more than their share from COVID-19 because of unequal access to vaccines, which have mostly gone to rich nations, Oxfam said in a report aimed at informing discussions at the World Economic Forum's online gathering of political and business leaders this week.

"The pandemic has been a billionaire bonanza," Oxfam International Executive Director Gabriela Bucher said in an interview. "When governments did the rescue packages and pumped trillions into the economy and to financial markets in order to support the economy for all, what happened is a lot of it went into the pockets of the billionaires."

Vaccine development has been one of the pandemic's success stories but Bucher said they've been "hoarded by the rich countries" seeking to protect pharmaceutical monopolies.

Since the pandemic erupted in March 2020, a new billionaire has been minted almost every day. The fortunes of the world's 10 richest men — including Elon Musk, Jeff Bezos and Bill Gates — more than doubled to $1.5 trillion, making them six times more wealthy than the world's poorest 3.1 billion people, Oxfam said.

Meanwhile, 160 million more people have been forced into poverty during the pandemic, Oxfam said, citing numbers from the Forbes 2021 Billionaires List, Credit Suisse's Global Wealth Databook and the World Bank.

Oxfam called for rich countries to waive intellectual property rules on COVID-19 vaccines in an effort to expand their production.

A one-off 99% tax on the 10 richest men's pandemic windfalls could earn more than $800 billion and be used to fund that effort and other progressive social spending, the group said.

The money "would be able to pay for vaccines for the whole world, have health systems for everyone," Bucher said. "We would also be able to compensate for the damage of climate change and have policies that address gender-based violence," while still leaving the 10 billionaires $8 billion richer than they were at the start of the pandemic, she added.

It's not all doom and gloom. The group noted that the U.S. and China, the world's two biggest economies, are starting to consider policies aimed at countering inequality, such as raising tax rates on the rich and taking action against corporate monopolies.

"The point is extreme inequality is not inevitable and this is why it brings us hope," Bucher said.

Oxfam has long sought to inspire debate at the annual gathering of business and political elites typically held in the Swiss ski resort of Davos. The pandemic forced organizers to put off the event for a second year, instead holding virtual sessions where political leaders will be joined by business executives and campaigning groups such as Oxfam.