Resurgence of Covid-19 in Brazil’s Amazon Dashes Hopes of Herd Immunity

The largest city in Brazil’s Amazon has closed bars and river beaches to contain a fresh surge of coronavirus cases, a trend that may dash theories that Manaus was one of the world’s first places to reach collective, or herd, immunity.

When a large portion of a community becomes immune to a disease, its spread becomes unlikely.

University of São Paulo (USP) researchers suggested that a drastic fall in Covid-19 deaths in Manaus pointed to collective immunity at work, but they also believe that antibodies to the disease after infection may not last more than a few months.

Local authorities on Friday enforced a 30-day ban on parties and other gatherings, and restricted restaurant and shopping hours, a setback for the city of 1.8 million after the worst of the pandemic seemed to be behind them.

In April and May, so many Manaus residents were dying from Covid-19 that its hospitals collapsed and cemeteries could not dig graves fast enough. The city never imposed a full lockdown. Non-essential businesses were closed but many simply ignored social distancing guidelines.

Then in June, deaths unexpectedly plummeted. Public health experts wondered whether so many residents had caught the virus that it had run out of new people to infect.

Research posted last week to medRxiv, a website distributing unpublished papers on health science, estimated that 44% to 66% of the Manaus population was infected between the peak in mid-May and August.

The study by the USP’s Institute of Tropical Medicine tested newly donated banked blood for antibodies to the virus and used a mathematical model to estimate contagion levels. The high infection rate suggested that herd immunity led to the dramatic drop in cases and deaths, the study said.

Daily burials and cremations fell from a peak of 277 on May 1 to just 45 in mid-September, according to the mayor’s office. The Covid-19 death toll that officially peaked at 60 on April 30, dropped to just two or three a day by the end of August.

Now the numbers are on the rise again.

The study’s lead researcher, Ester Sabino, declined to be interviewed for this article because the Manaus herd immunity study awaits peer review for publication.

Authorities warned Manaus residents they were ignoring the virus and risked a second wave of contagion by not wearing masks, packing into bars and attending parties. They shut down Manaus’ river beachfront where raves were being held.

Manaus Mayor Arthur Virgilio blamed right-wing President Jair Bolsonaro, who has minimized the gravity of the pandemic, for encouraging a return to normal life and work instead of waiting for a vaccine to be developed.

“The government must take this seriously and speak the truth. If it says there is no problem, that encourages people to ignore our decrees,” the mayor declared.

Epidemiologist Dr. André Patricio Almeida, of the Adventist Hospital of Manaus, said cases are rising again mostly among younger, wealthier people who go to bars who show milder symptoms but often infect older relatives who need to be treated in hospital.

Almeida said too little is known about Covid-19 and whether re-infection is possible to verify if herd immunity was reached in Manaus, but some short-lived immunity probably had been attained.

“There could be immunity that does not last for long,” Mayor Virgilio agreed.

The São Paulo University study said coronavirus antibodies appeared to wane after just a few months, which could explain the resurgence in Manaus.

“Something that became evident in our study – and that is also being shown by other groups – is that antibodies against SARS-CoV-2 decay quickly, a few months after infection,” one of its authors, Leis Buss, said in a statement by the São Paulo research foundation FAPESP that accompanied the paper.

“This is clearly occurring in Manaus,” Buss said.

This article was produced by the Thomson Reuters Foundation. Visit them at http://www.thisisplace.org

Tags:

You May Also Like

The Left in Brazil and Mexico Hopeful 2018 Will Bring Them Back to Power

Latin America is in limbo as the US’ “Operation Condor 2.0” has more or ...

Eike Batista talks in the Brazilian senate about corruption at BNDES - Wilson Dias/ABr

Once World’s Eighth Richest Man, Brazilian Gets 30 Years in Jail for Corruption

A Brazilian businessman famous for amassing and then losing a multi-billion-dollar fortune has been ...

Brazilian Army sent to protect the presidential palace in Brasília - Valter Campanato/ABr

Army Takes Over Brazil’s Capital After Protesters Invade and Break Government Buildings

The Brazilian Army took over positions close to the presidential palace and ministry buildings ...

Brazil Opens Research Centers for AIDS and TB

Brazil’s Ministry of Health plans to spend US$ 3 million (8 million reais) on ...

Brazilian military in the Amazon

Amazon Deforestation to Endanger Hydropower and Water Supply in Brazil’s Big Cities

Climate change will increase the burdens on Brazil’s armed forces and endanger the country’s ...

Drawings of the Yanomami spirit beings known as xapiri were projected onto Brazil's Congress buildings, in a historic first. © Adriano Machado/ISA

Brazil Congress Gets Petition with 400 Thousand Signatures Against Yanomami Genocide

A 439,000 signature petition calling on the Brazilian government to prevent the genocide of ...

Police in Vitória, in the state of Espírito Santo repress protests during June 30 general strike - Fernando Madeira/A Gazeta

Brazil’s General Strike Didn’t Stop the Country and Brought Little Damage

Brazil went through Friday’s general strike, the second of its kind called for by ...

Hypochondriacs They Are Not! 77% of Brazilians Call Selves Healthy or Very Healthy

IBGE, the Brazilian bureau of statistics, has just released the 2008 edition of its ...

A mural showing Bolsonaro holding a sign that says: 'It's just a minor cold' | Cris Faga/NurPhoto/PA Images

Brazil’s President Says Military Is Above Constitution and Threatens a Coup

Throughout the pandemic, Brazil’s president, Jair Bolsonaro, downplayed the threat posed by Covid-19. In ...

WordPress database error: [Table './brazzil3_live/wp_wfHits' is marked as crashed and last (automatic?) repair failed]
SHOW FULL COLUMNS FROM `wp_wfHits`