(CNN) – That sounds like the fear.
No buzzing banter and gossip, no sputtering of yellow and white taxis or Boda-Boda taxis. No gum or hip-hop music from the market stalls.
Just a terrible silence.
It was August 4, 2014, and the government of Sierra Leone had ordered more than 7 million citizens to enter and pray. The Ebola epidemic was out of control, and it was time for desperate measures.
Government officials knew the shutdown would not slow down the spread, but they wanted to get the entire population to take notice of it. They conducted temperature checks on roadblocks, isolation departments and emergency excavation teams to stop dying.
The disease would continue to claim more than 11,000 lives.
Ebola is now in another part of Africa.
Since the beginning of May, scientists, epidemiologists and doctors have been fighting an outbreak of the virus in the Democratic Republic of the Congo, the ninth to have been seen in the country.
"We are getting ready for the worst. This epidemic is on the cutting edge," Dr. Peter Salama, Head of the World Health Organization's Health Emergencies Program.
But this time – and for the first time in 40 years of fighting Ebola – global health experts have something to do with optimism.
Armed with an experimental vaccine and bolstered by a revolution in global health security that was introduced after the disaster of the West African epidemic, they believe they have a real chance to fatally extinguish Ebola.
Forty years of struggle
"There are two defining epidemics of our time: the AIDS epidemic and Ebola," said Peter Piot, director of the London School of Hygiene and Tropical Medicine.
The celebrated microbiologist Ha It was instrumental in fighting both diseases. He was the founding director of UNAIDS and discovered the Ebola virus that originated 40 years ago in the DRC, then in Zaire and today's South Sudan.
In August 1976, the director of the Yambuku School of Mission in the province of Équateur arrived in the ambulance of the catholic mission, led by Belgian nuns, with chills and fever. He had just made a two-week road trip north to the border of the Central African Republic, where he had bought smoked monkey meat.
He was first treated for malaria and returned home. But the director came back a week later with a cascade of more serious symptoms. In early September he died of profound bleeding.
More patients came soon, and the nuns unintentionally spread Mystery Disease through dirty needles.
A broken pool of blood from one of the infected nuns finally reached the Institute of Tropical Medicine Antwerp in Belgium, where Piot worked. He and his fellow scientists did not recognize the virus.
Piot was sent to Yambuku, the youngest member of a group of scientists investigating the mysterious outbreak.
"I've never been out in my life or in Africa, so I was not really qualified, but there were no other candidates," he said.
The symptoms he found were appalling. The patients bled from the inside out.
Ebola first hits the immune system, forms clots throughout the body, causing an immune system to "storm", attacking all of the body's vital organs and causing massive internal bleeding.
In the last stage, patients bleed from their eyes.
There are several strains of the Ebola virus. The Zaire tribe, which Piot was involved in identifying, can kill up to 90% of those infected, based on a history of outbreaks.
Piot and his colleagues called this new form of haemorrhagic fever Ebola virus disease after the nearby Ebola River. a tributary of the Congo River
The team stopped the outbreak in Yambuku by tracking contacts of suspect cases and each severely isolated, showing symptoms, a technique that was used for hundreds of years. Of the 318 suspected cases, 280 died.
Piot recalls how he drove from the field to London for an emergency meeting at the Tropical Medicine School, which he would one day lead. He says WHO and donor countries promised immediate investment.
"We'll never let that happen again," they said. Of course, what happened? Nothing, "said Piot.
But it happened again – and again – and then there was the year 2014.
Like this first outbreak in 1976, the West African epidemic had a modest, if tragic, origin.
Seven months before Sierra Leone shut down the land, the eruption began with an 18-month outbreak Young Emile in neighboring Guinea
Scientists from WHO and Guinea believe that Emile is the Ebola virus of bats near his home He died and spread the disease to his immediate family.
From then on, the virus infected more victims secretly, secretly, by sick workers and traditional burial practices in which mourners bathed the dead International complacency quickly swept Ebola across the borders and into the cities.
"Even after several months There was a lot of talk and little action, "said Stefan Kruger, a physician without borders, who was stationed in a treatment center in Sierra Leone. "This could make the spread of the virus out of control."
The world finally noticed when US Ebola patients appeared in US hospitals in isolation chambers, flanked by doctors in "space suits."
The Outlook A global pandemic triggered global action.
The WHO and foreign governments, according to their own statements and devastating independent reports of the Ebola reaction, were awakened far too late by the threat.
When the WHO announced the outbreak in 2016, the final burden was devastating.
There were officially 28,616 suspected cases in the West African epidemic and 11,310 deaths, although field doctors say the death toll is likely to be much higher. Today there are more than 20,000 Ebola orphans in West Africa.  Sierra Leone, Guinea and Liberia lost more than $ 2 billion in economic growth in 2015 alone, according to the World Bank.
Breakthroughs – But Too Late
Some form of vaccine development for Ebola has been in the works for decades, but a horrific virus that has afflicted limited people in remote parts of the globe has not provided rich countries and pharmaceutical countries with enough incentive to invest ,
"For many dangerous pathogens affecting developing countries, and especially in this case sub-Saharan Africa, it is very difficult to find an interest from manufacturers in the market because there is no more lucrative market for these products," said the Salama of the WHO.
Before the outbreak in West Africa, Ebola was not as dangerous as the flu, which kills up to 646,000 people people, according to the US Centers for Disease Control and Prevention every year.
Another limitation was the fact that vaccine development for a virus like Ebola can only be done in select four-level laboratories. Just to look at it through a microscope, scientists have to be in pressure suits.
But both Piot and Salama agree that the threat of Ebola required vaccination – and one that could have come much earlier.
As tragic as it was, the magnitude of the epidemic in 2014 is forcing governments, WHO and pharmaceutical companies to take more seriously emerging pathogens – diseases that have recently emerged or recently spread throughout the population ,
The most promising The experimental Ebola vaccine was accelerated to production and tested late in the outbreak in West Africa. The study proved to be extremely effective, with one study showing 100% efficacy
Canadian government scientists developed the vaccine in the mid-2000s, now called rVSV-ZEBOV.
In simple words, the vaccines with the VSV virus mimic an immune response in the body to the Ebola virus.
"The team used modern technology to bring the outer envelope of the Ebola virus into the benign VSV virus, and with additional modifications it basically gave it ebola makeup," Dr. Guillaume Poliquin, senior medical adviser to the Canadian National Healthcare Administration's National Microbiology Lab.
Merck is now producing the vaccine in large quantities.
A booster-style vaccine that could provide even longer protection is also in advanced stages of development by Johnson & Johnson. It has been tested on thousands of volunteers.
For the first time in the face of an outbreak, doctors can give real hope to Ebola patients and their families.
Detective work in the forest
The eruption in Congo is in many respects very similar to the early stages of the West African eruption.
The disease spreads to the heavily forested northwest of the country near the border from the Central African Republic and the Republic of Congo – and, as in West Africa, the risk of a regional epidemic is very real.
The first recorded cases of the eruption came from the remote wooded area of Bikoro, but soon spread to Mbandaka, an important port city and a regional gateway. Ebola could spread along the Congo and increase the prospects of an outbreak in the capital, Kinshasa, with more than 10 million inhabitants.
However, unlike the countries affected in 2014, the Congo has a proven track record in fighting Ebola flares.
"We've been involved with Ebola since 1976, so we've developed the expertise and speed to respond to these outbreaks." said Dr. Oly Ilunga Kalenga, Minister of Health of the country.
Their teams must be as many detectives as health workers.
To curb the spread, the contacts of all suspected cases are exhaustively monitored and monitored. In urban environments, the contacts are exponentially higher, but in the deep forest they are much harder to find.
Doctors in the Congo say they are not even close to the phase in which they control the outbreak. You must first track the chains of transmission.
The single-dose experimental vaccine was used and injected into health workers – often the most vulnerable – and fanned out by a vaccination campaign in which contacts of cases are made, and then their contacts are vaccinated in ever-increasing rings to stamp out the spread.
The ring vaccination strategy was used against smallpox in the 1970s until it was officially eradicated in 1980.
But in the Congo this will be the case an enormous logistical challenge.
Airlifts and Motorcycles
The vaccine must be stored at minus 70 degrees Celsius, so that an airlift has been established that connects aircraft with UN choppers and then motorcycles then comb through the single lane forest roads at the epicenter of the outbreak.
The speed at which WHO has responded shows an important paradigm shift as of 2014. Just days after the announcement of Ebola, thousands of doses of the vaccine were in the country.
"They are not waiting for the first Western human to fall ill and say," Oh, my God, we need to activate the emergency. "That's a big change," said Luis Encinas, a physician at Medecin's Sans Frontieres working in the epicenter in northwest Congo.
Compared to 2014, global powers, UN agencies and affected countries seem to take their role in global health security much more seriously, experts agree.
"We are very much aware of our position and our role in global health security agenda," said Kalenga, the minister of health who personally oversees the vaccination campaign.
But it is still early in this outbreak, and much could go wrong, as was the case of two patients who died from isolation in Mbandaka this week – possibly a new chain of transmission in the city.
According to Salama, workers must convince local people that health workers, often covered in terrifying protective gear from head to toe, are helping.
"There are always two epidemics: one of the virus and one of anxiety." He said.
CORRECTION: This story has been updated to reflect that the Democratic Republic of the Congo was once referred to as Zaire.