Hard-hit Brazil closed out its deadliest month of the coronavirus pandemic by far on Wednesday, with 66,573 people killed by Covid-19 in March, more than double the previous record.

An explosion of severe cases has overwhelmed many of the country's hospitals, forcing doctors to make agonizing decisions over whom to give life-saving care and raising fears the new chapter of the crisis could spread beyond Brazil.

The health ministry recorded more than twice as many fatalities in March as Brazil's second-deadliest month of the pandemic, July 2020, when there were 32,881 deaths.

"Never in Brazilian history have we seen a single event kill so many people" in one month, said doctor Miguel Nicolelis, former coordinator of the pandemic response team for Brazil's impoverished northeast.

With the southern hemisphere winter now approaching and the virus spreading fast, Brazil is facing "a perfect storm," he told AFP.

Covid-19 patients in Brazil are treated in a field hospital set up in a gym in the town of Santo Andre on March 26, 2021
Covid-19 patients in Brazil are treated in a field hospital set up in a gym in the town of Santo Andre on March 26, 2021 AFP / Miguel SCHINCARIOL

"That's a threat not just for Brazil but for the entire world."

Brazil's average daily death toll has more than quadrupled since the start of the year, to 2,976 this week, the highest by far worldwide.

The 24-hour death toll reported by the health ministry Wednesday also set a new record: 3,869.

Health experts say the recent surge of cases in the sprawling South American country of 212 million people is partly driven by a local variant of the virus known as P1.

Believed to be more contagious, P1 can re-infect people who have had the original strain of the virus, and has spread to more than two dozen countries, including the United States, Britain and Japan.

Covid-19 patients in Brazil are treated in a field hospital set up in a gym in the town of Santo Andre on March 26, 2021
Covid-19 patients in Brazil are treated in a field hospital set up in a gym in the town of Santo Andre on March 26, 2021 AFP / Miguel SCHINCARIOL

As long as the pandemic continues to rage unchecked in Brazil, there is a risk that more variants could emerge in the country, researchers say.

President Jair Bolsonaro faces mounting criticism for his handling of the pandemic.

The far-right leader's resistance to lockdowns, face masks and vaccines has caused a firestorm of controversy as Covid-19 has claimed more than 321,000 lives in Brazil, second only to the United States.

Under pressure from allies in Congress and the business world, Bolsonaro installed his fourth health minister of the pandemic last week, replacing Eduardo Pazuello -- an army general with no medical experience -- with cardiologist Marcelo Queiroga.

A man is inoculated against the coronavirus with a CoronaVac vaccine at the Justice Palace in Rio de Janeiro on March 31, 2021
A man is inoculated against the coronavirus with a CoronaVac vaccine at the Justice Palace in Rio de Janeiro on March 31, 2021 AFP / Mauro PIMENTEL

The president sought to show he was taking the pandemic seriously, launching a crisis committee.

However, he reverted to his anti-lockdown message at the committee's first meeting Wednesday.

"We're not going to solve the problem by staying at home," he said -- contradicting his new health minister, who had just urged Brazilians to "respect social distancing."

Bolsonaro argues the economic damage of lockdowns is worse than the virus itself, a stance that has left state and local governments to implement a messy patchwork of pandemic policies.

Brazil is meanwhile struggling to secure enough vaccine doses, and is far off pace to meet the health ministry's target of immunizing the entire adult population by the end of the year.

Brazil is currently using two vaccines, Oxford/AstraZeneca's and Chinese-developed CoronaVac, both of which require two doses.

About eight percent of the population has received a first dose and 2.3 percent a second.

Health regulators granted emergency approval Wednesday for Johnson & Johnson's single-dose vaccine, but the 38 million doses Brazil has purchased will only start arriving in August.

"We're at the worst moment of the pandemic, and indications are that April will be very bad, too," said epidemiologist Ethel Maciel of Espirito Santo Federal University.

"The worst is yet to come," she told AFP.

Covid-19 beds in intensive care units are more than 90 percent full in 18 of Brazil's 27 states, and another seven states are approaching that level.

At least 230 patients with suspected or confirmed cases of Covid-19 died waiting for a bed in intensive care in Sao Paulo this month, according to TV Globo.

Several states have begun implementing protocols to decide which patients get ICU care, prioritizing those most likely to survive.

"We're in a very tragic situation," said Maciel.