News / Africa

In Cameroon, TB Vaccine Breakthrough Elusive

Tuberculosis vaccine breakthrough eludes researchers in Cameroon due to 'clever' nature of TB-causing bacteria

Multimedia

Audio

Deaths from tuberculosis are increasing in the developing world and especially in Africa.  It’s the world’s second deadliest infectious disease after HIV/AIDS.  In 2008, nearly two million people died of TB and researchers warn that mortality rates will surge further if new drugs and vaccines are not developed.

Linda is a 35-year-old Cameroonian mother of two.  She’s one of 35.000 people in the country diagnosed every year with tuberculosis, which kills some 7,000.  Her problem is compounded by the fact that she’s also infected with HIV, the virus that causes AIDS.

X-ray of patient with tuberculosis
X-ray of patient with tuberculosis

“It is very difficult,” she said. “Several times, I consider suicide but then I think about my children and want to be there for them.  I have had TB for several years and despite all the drugs, I am still ill.  The doctor says my problem is severe because I also have HIV.  I have to take countless numbers of medicines every day and sometimes I just can’t stand it.”

Like others in her condition, Linda longs for the day when an effective remedy will be found.

In early October, more than 200 researchers met for an international symposium in the Cameroonian capital, Yaounde.  They discussed the disease, but had no new drugs or vaccines to report.  They could only talk about new ways to improve existing treatments.

The meeting was hosted by the Novartis Institute for Tropical Diseases, a non-profit research organization trying to find new medicines for the treatment of neglected, infectious diseases like TB, malaria and Dengue fever.

One of the conference participants, Prof. Barry Clifton of the US National Institutes of Health, says the absence of new drugs is steadily increasing the number of deaths from TB:

“I don’t feel very optimistic about a breakthrough any time in the foreseeable future unless people put more effort and emphasis and research into tackling TB,” he said.  “At our current level, I think we’ll keep the pace to the point where we hopefully don’t have many people who don’t have any options.  But we’re not going to win the race.”

Paul Herrling in a discussion with symposium attendee
Paul Herrling in a discussion with symposium attendee

The only available vaccine for TB, known as Bacille-Calmette-Guerin (BCG) was developed almost 90 years ago.  It’s a live vaccine similar to the TB bacterium and has been improved over the years to provide immunity with the first dose.

But while it reduces risks of severe forms of TB in early childhood, it is not very effective in adults, who can be infected even if they were vaccinated in their youth. And BCG is not safe for children with HIV because it can spur the onset of the disease in those with weakened immune systems.  Across Africa, most children are given the vaccine without knowledge of their HIV status.

The link Between HIV and TB

Prof. Paul Herrling is head of the Novartis Institutes for Developing World Medical Research. He says there are a number of reasons for the current dilemma:

“The first one is that the last medicines that we had for TB are about 40 years old, and one thing that people did not know at that time is that this is a very clever bacterium and when they’re treated with the same medicines for a long time, they learn to escape it.  That’s what we call resistance,” he said.

Scientists say TB strains can vary from multi-drug resistant (MDR-TB) to extensively drug resistant (XDR-TB).

The most prominent way the TB virus gains resistance is in patients’ failing to complete their treatments.

Researchers say fighting tuberculosis is made more difficult by the increasing number of people, especially in Africa, like Linda, who are also infected with HIV.  Prof. Christopher Kuaban of the University of Yaounde in Cameroon says HIV/AIDS patients are up to 20 times more likely to develop TB than people without HIV:

“HIV is an infection that destroys your immune system. TB is contained by this immune system – so if your immune system breaks down when you’re infected by TB, the TB germ has nothing to fear because there’s nobody to destroy it. That’s why in any country where HIV is common, TB becomes very common,” he said.

Ongoing research inconclusive

Current treatment is cumbersome: it takes six to nine months and patients must take several tablets several times a day.  Research in several parts of the world is focusing on developing treatment that’s easier for the patient, as well as vaccines that may replace BCG.

Clinical trials are about to begin on one vaccine candidate - called AERAS-422.  They will be conducted in Kenya, South Africa, Uganda and India by the non-profit research organization Aeras Global TB Vaccine Foundation.  It recently obtained a $785,000 three-year-grant from the U.S. Food and Drug Administration.  Officials say the results may be available by the year 2020.

University of Yaounde (Cameroon) TB
University of Yaounde (Cameroon) TB

Funding is a problem say researchers like Barry Clifton:

“A normal pharmaceutical company will take a hundred people working for several years to get a candidate to put into clinical trials," he said. "With TB, we don’t have those kinds of resources because it’s a developing world disease, and there’s no financial incentive.  So, we try to do the best we can with the small resources we have.  It’s market-driven, so the big pharmaceutical companies are responsible for making money [for their shareholders].”

Meantime, the epidemic continues to grow, especially in Africa, where cities are increasingly crowded, where poor people find little to eat to bolster their immune systems, and where healthcare services are not adequate.

As a result, more and more people like Linda and her children are victims of stigma and discrimination. They are increasingly turning their backs on hospitals and heading for traditional healers and proliferating prayer churches for help.

TB’s intimidating complexities

TB is caused by a bacterium known as the Mycobacterium tuberculosis.  It’s spread from person to person through tiny airborne droplets of infected sputum.  It can affect almost any tissue or organ in the body, with the most common site being the lungs.  Basically, it cripples the human immune system, leaving patients vulnerable to deadly bacterial infection.

The WHO says of the nine million people diagnosed with TB worldwide last year, a third live in Africa.  It’s currently the leading cause of death among people with HIV/AIDS on the continent.

You May Like

Lion Cecil's Killing Sparks 'Canned Hunting' Debate in S. Africa

Conservationists believe incident, which triggered worldwide outrage, will reshape debate about practice in which hunters are allowed to target animals bred for hunting More

Taliban's New Leader Says Jihad Will Continue

Top US Afghan diplomat also meets with Pakistani, Afghan officials following news of Mullah Omar's death More

Environmentalists Issue Warning on Mekong Biodiversity

Scientists say decades of economic development, hydropower-dam construction, lax law enforcement and trafficking have taken their toll More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Astronauts Train Underwater for Deep Space Missionsi
|| 0:00:00
...    
🔇
X
George Putic
July 30, 2015 8:59 PM
Manned deep space missions are still a long way off, but space agencies are already testing procedures, equipment and human stamina for operations in extreme environment conditions. Small groups of astronauts take turns in spending days in an underwater lab, off Florida’s southern coast, simulating future missions to some remote world. VOA’s George Putic reports.
Video

Video Astronauts Train Underwater for Deep Space Missions

Manned deep space missions are still a long way off, but space agencies are already testing procedures, equipment and human stamina for operations in extreme environment conditions. Small groups of astronauts take turns in spending days in an underwater lab, off Florida’s southern coast, simulating future missions to some remote world. VOA’s George Putic reports.
Video

Video Civil Rights Leaders Struggled to Achieve Voting Rights Act

Fifty years ago, lawmakers approved, and U.S. President Lyndon Johnson signed, the Voting Rights Act of 1965. The measure outlawed racial discrimination in voting, giving millions of blacks in many parts of the southern United States federal enforcement of the right to vote. Correspondent Chris Simkins introduces us to some civil rights leaders who were on the front lines in the struggle for voting rights.
Video

Video Booming London Property a ‘Haven for Dirty Money’

Billions of dollars of so-called ‘dirty money’ from the proceeds of crime - especially from Russia - are being laundered through the London property market, according to anti-corruption activists. As Henry Ridgwell reports from the British capital, the government has pledged to crack down on the practice.
Video

Video Hometown of Boy Scouts of America Founder Reacts to Gay Leader Decision

Ottawa, Illinois, is the hometown of W.D. Boyce, who founded the Boy Scouts of America in 1910. In Ottawa, where Scouting remains an important part of the legacy of the community, the end of the organization's ban on openly gay adult leaders was seen as inevitable. VOA's Kane Farabaugh reports.
Video

Video 'Metal Muscles' Flex a New Bionic Hand

Artificial limbs, including the most complex of them – the human hand – are getting more life-like and useful due to constant advances in tiny hydraulic, pneumatic and electric motors called actuators. But now, as VOA’s George Putic reports, scientists in Germany say the future of the prosthetic hand may lie not in motors but in wires that can ‘remember’ their shape.
Video

Video Russia Accused of Abusing Interpol to Pursue Opponents

A British pro-democracy group has accused Russia of abusing the global law enforcement agency Interpol by requesting the arrest and extradition of political opponents. A new report by the group notes such requests can mean the accused are unable to travel and are often unable to open bank accounts. VOA's Henry Ridgwell reports.
Video

Video 'Positive Atmosphere' Points Toward TPP Trade Deal in Hawaii

Talks on a major new trade agreement among 12 Pacific Rim nations are said to be nearing completion in Hawaii. Some trade experts say the "positive atmosphere" at the discussions could mean a deal is within reach, but there is still hard bargaining to be done over many issues and products, including U.S. drugs and Japanese rice. VOA's Jim Randle reports.
Video

Video Genome Initiative Urgently Moves to Freeze DNA Before Species Go Extinct

Earth is in the midst of its sixth mass extinction. The last such event was caused by an asteroid 66 million years ago. It killed off the dinosaurs and practically everything else. So scientists are in a race against time to classify the estimated 11 million species alive today. So far only 2 million are described by science, and researchers are worried many will disappear before they even have a name. VOA’s Rosanne Skirble reports.
Video

Video Scientists: One-Dose Malaria Cure is Possible

Scientists have long been trying to develop an effective protection and cure for malaria - one of the deadliest diseases that affects people in tropical areas, especially children. As the World Health Organization announces plans to begin clinical trials of a promising new vaccine, scientists in South Africa report that they too are at an important threshold. George Putic reports, they are testing a compound that could be a single-dose cure for malaria.
Video

Video 'New York' Magazine Features 35 Cosby Accusers

The latest issue of 'New York' magazine features 35 women who say they were drugged and raped by film and television celebrity Bill Cosby. The women are aged from 44 to 80 and come from different walks of life and races. The magazine interviewed each of them separately, but Zlatica Hoke reports their stories are similar.
Video

Video US Calls Fight Against Human Trafficking a Must Win

The United States is promising not to give up its fight against what Secretary of State John Kerry calls the “scourge” of modern slavery. Officials released the country’s annual human trafficking report Monday – a report that’s being met with some criticism. VOA’s National Security correspondent Jeff Seldin has more from the State Department.
Video

Video Washington DC Underground Streetcar Station to Become Arts Venue

Abandoned more than 50 years ago, the underground streetcar station in Washington D.C.’s historic DuPont Circle district is about to be reborn. The plan calls for turning the spacious underground platforms - once meant to be a transportation hub, - into a unique space for art exhibitions, presentations, concerts and even a film set. Roman Mamonov has more from beneath the streets of the U.S. capital. Joy Wagner narrates his report.
Video

Video Europe’s Twin Crises Collide in Greece as Migrant Numbers Soar

Greece has replaced Italy as the main gateway for migrants into Europe, with more than 100,000 arrivals in the first six months of 2015. Many want to move further into Europe and escape Greece’s economic crisis, but they face widespread dangers on the journey overland through the Balkans. VOA's Henry Ridgwell reports.
Video

Video Stink Intensifies as Lebanon’s Trash Crisis Continues

After the closure of a major rubbish dump a week ago, the streets of Beirut are filling up with trash. Having failed to draw up a plan B, politicians are struggling to deal with the problem. John Owens has more for VOA from Beirut.
Video

Video Paris Rolls Out Blueprint to Fight Climate Change

A U.N. climate conference in December aims to produce an ambitious agreement to fight heat-trapping greenhouse gases. But many local governments are not waiting, and have drafted their own climate action plans. That’s the case with Paris — which is getting special attention, since it’s hosting the climate summit. Lisa Bryant takes a look for VOA at the transformation of the French capital into an eco-city.

VOA Blogs