Every adult in the world could get a Covid-19 vaccine if the wealth billionaires collected during the pandemic was taxed 99% once, according to an analysis published on Thursday by several groups that advocate for economic equity.

This one-time tax on the world’s 2,690 billionaires could also cover $20,000 in cash paid to all unemployed workers, according to the analysis by Oxfam, the Fight Inequality Alliance, the Institute for Policy Studies and the Patriotic Millionaires.

That tax would still leave the billionaires with $55bn more than they had before the pandemic, the analysis said.

Morris Pearl, the former managing director of BlackRock, the world’s largest asset manager, said in a statement countries could no longer bear “the surge in global billionaire wealth as millions of people have lost their lives and livelihoods”.

Pearl, now the chair of Patriotic Millionaires, a group of wealthy people who support higher taxes on the wealthy, said governments have historically used wealth taxes after crises to help communities rebuild.

During the first world war, the US increased its tax rate for people with the highest incomes to 67%. In the second world war, President Franklin Delano Roosevelt tried to cap individual income at $25,000. In December last year, Argentina put in place a one-off tax on people with more than 200m Argentinian pesos ($2.5m, GBP1.8m) that had raised 223bn pesos ($2.4bn) as of May.

“Our economies are choking on this hoarded resource that could be serving a much greater purpose,” Pearl said. “Billionaires need to cough up that cash ball – and governments need to make them do it by taxing their wealth.”

The analysis used data from the financial magazine Forbes, which showed that billionaires increased their wealth by $5.5tn from 18 March 2020 to 31 July 2021. The increase over 17 months was greater than the $5.4tn billionaires gained in the 15 years from 2006 to 2020, the analysis said.

Each vaccine dose is estimated to cost $7 in the analysis, which determined two doses for 5 billion adults would cost $70bn.

At least one dose of the Covid-19 vaccine has been administered to 30.7% of the world’s population, but only 1.2% of people in low-income countries have received a first dose.

To determine how much money from the one-time tax could go to unemployed workers, the group looked at a February report by the International Labour Organization, which found that 220 million people were unemployed globally.

In an unprecedented move last month, four multilateral institutions, including the International Monetary Fund (IMF) and the World Health Organization (WHO), warned the global economic recovery will be held back unless there is more equity in vaccine distribution.

The economists Emmanuel Saez and Gabriel Zuckman warned in the preface of the 2020 edition of their book about how rich Americans dodge taxes, Triumph of Injustice, that while crises are usually bad for the wealthy, the Covid-19 pandemic “may turn out to be different”.