Sello Kgoale watched his neighbors shuttling back and forth with looted liquor, refrigerators and flat-screen televisions. There were no police at a nearby mall, they told him, so the 46-year-old father of three joined the thousands-strong mob ransacking the shopping center and filled three bags with rice, cooking oil and paraffin for his family’s cooking stove.

“I’ve never done anything like this before. I’m ashamed,” he said last week, sitting in his corrugated-iron shack. “But we just keep getting hit.”

Sixteen months ago, Mr. Kgoale lived in a rented two-bedroom house and had a steady cleaning job, while his wife worked in a call center. South Africa’s first wave of Covid-19 infections took the lives of his mother-in-law and grandmother. The second cost him his job and then his home. The third destroyed his efforts to start a new business. “I came to Johannesburg 21 years ago from the north, full of hope,” he said. “Now we have nothing left but anger.”

Wave after wave of coronavirus is pummeling South Africa’s fragile economy and its largely unvaccinated population, creating a spiral of death, lockdowns and anger that has fueled the country’s worst rioting since the collapse of white minority rule in 1994. At least 215 people died in the violence across South Africa’s two most populous provinces, and more than 3,400 have been arrested. While the looting had quieted by Monday, the situation remains tense in parts of the country.

The violence was initially sparked by the arrest of former President Jacob Zuma earlier this month, and has exacerbated a power struggle within the African National Congress, South Africa’s ruling party since Nelson Mandela’s election as the country’s first Black president 27 years ago. President Cyril Ramaphosa has said the unrest was an attempted insurrection against South Africa’s democracy and intended to sabotage its economy.

The political protest quickly devolved, becoming an outlet for the frustrations of an impoverished majority long shut out of the country’s economy. South Africa is struggling to emerge from a record contraction of 7% last year. Each surge of Covid-19 and the subsequent lockdowns are putting more pressure on the divided nation, where 43% of workers were without a job at the end of March.

“We were sitting on a dormant volcano here, where all of us might perish if it erupts,” said Xolani Dube, a political analyst with the Xubera Institute for Research and Development, a nonpartisan think tank in the southeastern city of Durban. “Now the volcano has erupted.”

The human and economic dislocation in South Africa, where just 2.8% of people have been fully vaccinated against Covid-19, shows how difficult it will be for many emerging economies to recover from the pandemic. The violence in South Africa—as well as in countries including Colombia and Sudan—offers a stark example of how diminishing incomes and the rising cost of food are adding to more than a year of pandemic suffering, exacerbating political instability.

The World Bank estimates that more than 160 million people will have been pushed into poverty as a result of Covid by the end of 2021, widening the gap between the world’s richest and poorest nations. The pandemic has led 41 million people to the brink of famine, according to the World Food Program.

In South Africa, Mr. Ramaphosa called in army reservists to restore law and order, while the country’s overcrowded hospitals and first responders fought the country’s third, and highest, surge in Covid-19 infections.

When the pandemic arrived, South Africa was already, by some measurements, the most inequitable country on earth. Nearly two-thirds of Black South Africans, who make up around 80% of the country’s population, lived in poverty, according to the national statistics office. The mean monthly income of white South Africans was more than three times that of their Black compatriots.

Mr. Ramaphosa, elected on a pledge to clean up the country’s corruption-riddled politics and revive a moribund economy, imposed one of the world’s strictest lockdowns in response to Covid-19.

In the economic downturn that followed, low-income earners, many of whom are Black or members of other racial groups disadvantaged under apartheid, were nearly four times as likely to lose their jobs as high-income earners, the World Bank said in a report this month. Some 13 million South Africans, including three million children, live in households that no longer have enough money to afford food, a recent, nationally representative survey found.

South Africa has lost more than 190,000 of its 60 million citizens—about one in 300—to the coronavirus since May 2020, according to a tally of excess deaths by the government-funded South African Medical Research Council. A nationwide study of donated blood determined that by May this year, 47% of South Africans have already had Covid-19, with Black donors more than three times as likely to have antibodies to the virus than white donors.