RIO DE JANEIRO — Just a few weeks ago, Covid-19 spread with alarming ease across a cluster of countries in South America, overwhelming hospital systems and killing thousands of people every day.
Suddenly, the region that was the epicenter of the pandemic breathes a sigh of relief.
New infections have fallen sharply in almost every country in South America as vaccination rates have risen. The delay has been so sharp and rapid, even as the Delta variant wreaks havoc elsewhere in the world, that experts can’t quite explain it.
Brazil, Argentina, Chile, Peru, Colombia, Uruguay and Paraguay saw dramatic increases in cases in the early months of the year, just as vaccines began arriving in the region. The containment measures were uneven and largely lax as governments were desperate to jump-start ailing economies.
“Now the situation across South America has cooled down,” said Carla Domingues, an epidemiologist who led Brazil’s immunization program until 2019. “It’s a phenomenon that we don’t know how to explain.”
There are no new sweeping or large-scale containment measures in the region, although some countries have imposed strict border controls. A major factor in the recent drop in cases, experts say, is the speed with which the region finally succeeded in vaccinating people. Governments in South America have generally not dealt with the kind of apathy, politicization and vaccine conspiracy theories that left much of the United States vulnerable to the highly contagious Delta strain.
In Brazil, which has seen a slow, chaotic vaccine rollout, nearly 64 percent of the population has received at least one dose of a vaccine, a rate higher than that in the United States. That prompted President Jair Bolsonaro, who had initially raised doubts about vaccines, to brag last month.
“Brazil has one of the best vaccination records worldwide,” he said in a Twitter post.
In Chile and Uruguay, more than 70 percent of the population is fully vaccinated.
As the number of cases has declined, schools across much of the region have resumed face-to-face classes. Airports are getting busier as more people travel for work and leisure.
The drop in the number of files last week prompted the United Nations to issue a more optimistic forecast of economic growth in the region. It now expects economies in Latin America and the Caribbean to grow 5.9 percent this year, up slightly from its estimate of 5.2 in July.
“We have managed to delay the wide spread of the Delta variant and continue with the largest vaccination campaign in our history,” Argentina’s health minister Carla Vizzotti said last week.
In Argentina, more than 61 percent of the population has received at least one dose of a vaccine.
Chrystina Barros, a health expert at the Federal University of Rio de Janeiro, said she is concerned that declining caseloads will lead people to become complacent about wearing masks and avoiding crowds, while the epidemic remains a threat.
“There is a serious risk of the vaccine’s effectiveness being compromised,” she said. “The cooling of the pandemic cannot inspire people to relax due to the crisis.”
Jairo Méndez Rico, a viral disease expert who advises the World Health Organization, said the Delta variant may have been slow to take off in South America because so many people in the region have natural immunity to having the virus. But he said the variant could still lead to new peaks.
Understanding Vaccine and Mask Mandates in the US
- Vaccine Rules. On August 23, the Food and Drug Administration gave full approval to Pfizer-BioNTech’s coronavirus vaccine for people 16 and older, paving the way for an increase in mandates in both the public and private sectors. Private companies are increasingly mandating vaccines for employees. Such mandates are permitted by law and have been confirmed in court proceedings.
- Mask Rules. The Centers for Disease Control and Prevention recommended in July that all Americans, regardless of vaccination status, wear masks in indoor public places in areas with outbreaks, a reversal of the guidance it offered in May. Find out where CDC guidelines apply and where states have their own masking policies. The battle over masks has become controversial in some states, with some local leaders defying state bans.
- College and universities. More than 400 colleges and universities are demanding that students be vaccinated against Covid-19. Nearly all of them are in states that voted for President Biden.
- schools. Both California and New York City have introduced vaccine mandates for educators. A survey published in August found that many U.S. parents of school-aged children are opposed to mandatory vaccines for students, but were more in favor of mask mandates for students, teachers and staff who have not received their injections.
- Hospitals and Medical Centers. Many hospitals and major health systems require workers to receive a Covid-19 vaccine, citing the increasing caseload fueled by the Delta variant and persistently low vaccination coverage in their communities, even within their workforce.
- New York City. Evidence of vaccination is required from employees and customers for indoor meals, gyms, performances and other indoor situations, although enforcement will not begin until September 13. Teachers and other education workers in the city’s vast school system must have at least one vaccine dose by Sept. 27, without the option of weekly testing. City hospital employees should also receive a vaccine or be tested weekly. Similar rules apply to employees in New York State.
- At the federal level. The Pentagon announced it would aim to make coronavirus vaccinations mandatory for the country’s 1.3 million active-duty troops “by mid-September.” President Biden announced that all civilian federal employees would be required to be vaccinated against the coronavirus or undergo regular testing, social distancing, mask requirements and restrictions on most travel.
“It’s not easy to explain,” he said. “It’s too early to say what’s going on.”
Despite the uncertainty, governments in South America are set to reopen borders in the coming months. Argentina’s President Alberto Fernández said in late July that the path to normalcy was in sight.
“We deserve a different life, a life where we enjoy music, painting, sculpture, movies, theater,” he said. “A life where we can laugh without a face mask, where we can hug the people we love.”
Jennifer Mac Donnell, a Buenos Aires esthetician, is days away from a mid-September wedding — a milestone that felt uncertain for much of the year.
“We feared we would be forced to cancel it,” the 39-year-old said. “Now we are much calmer, there are fewer cases, most of our friends are vaccinated and everyone is just focused on having fun.”
Daniel Politi reported from Buenos Aires, and Flávia Milhorance from Rio de Janeiro.