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

Video Afghan Refugees Complain of Harassment in Pakistan

Afghan officials and human rights organizations assert that Pakistani authorities are using deadly attack at school in Peshawar as pretext to push out Afghan refugees More

At Boston Bombing Hearing, Sides Spar Over Boat

At final pre-trial hearing, lawyers for suspect Dzhokhar Tsarnaev, prosecutors disagree on whether vessel where he hid from police can be shown to jurors More

Iran Judiciary 'Picks' Lawyer for Detained WP Reporter

Masoud Shafii has been attempting to secure official recognition as Rezaian’s attorney, but is not allowed to see his client in prison 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.
US Supreme Court Hears Hijab Discrimination Casei
X
Katherine Gypson
February 25, 2015 11:30 PM
The U.S. Supreme Court has heard opening arguments in a workplace religious discrimination case that examines whether a clothing store can refuse to hire a young woman for wearing the headscarf she says is a symbol of her Muslim faith. Katherine Gypson reports from the Supreme Court.
Video

Video US Supreme Court Hears Hijab Discrimination Case

The U.S. Supreme Court has heard opening arguments in a workplace religious discrimination case that examines whether a clothing store can refuse to hire a young woman for wearing the headscarf she says is a symbol of her Muslim faith. Katherine Gypson reports from the Supreme Court.
Video

Video Falling Gas Prices Hurt Nascent Illinois Hydraulic Fracturing Industry

Falling oil prices are helping consumers purchase cheaper petroleum at the pump. But that’s made hydraulic fracturing or “fracking” less economically viable for the companies in the United States invested in the process. VOA’s Kane Farabaugh reports on one Midwestern town that was hoping to change its fortunes by cashing in on the next big U.S. oil boom.
Video

Video Fighting in Sudan's South Kordofan Fuels Mass Displacement

Heavy fighting in Sudan's South Kordofan state is causing hundreds of thousands to flee into uncertain conditions. Local aid organizations estimate as many as 400,000 civilians have been internally displaced since the conflict began more than three years ago, while another 250,000 have fled across the border to refugee camps in South Sudan. VOA's Adam Bailes reports.
Video

Video Lao Dam Project Runs Into Opposition

A Lao dam project on a section of the Mekong River is drawing opposition from local fishermen, international environmental groups and neighboring countries. VOA's Say Mony visited the region to investigate the concerns. Colin Lovett narrates.
Video

Video A Filmmaker Discovers Her Biracial Identity in "Little White Lie

Lacey Schwartz grew up in an upper middle-class Jewish family, in a town in upstate New York where almost everyone she knew was white. She assumed that she was, as well. Her recent documentary, Little White Lie, tells the story of how she uncovered the secret of her true racial background. VOA’s Carolyn Weaver has more on the film.
Video

Video Deep Under Antarctic Ice Sheet, Life!

With the end of summer in the Southern hemisphere, the Antarctic research season is over. Scientists from Northern Illinois University are back in their laboratory after a 3-month expedition on the Ross Ice Shelf, the world’s largest floating ice sheet. As VOA’s Rosanne Skirble reports, they hope to find clues to explain the dynamics of the rapidly melting ice and its impact on sea level rise.
Video

Video US-Cuba Normalization Talks Resume Friday

Negotiations aimed at normalizing diplomatic relations between the U.S. and Cuba resume Friday. On the table: lifting a half-century trade embargo and easing banking and travel restrictions. There's opposition in Congress, but some analysts say there may be sufficient political and economic incentives in both nations for a potential breakthrough this year. VOA's Mil Arcega reports.
Video

Video Pakistan's Deadline For SIM Registration Has Cellphone Users Scrambling

Pakistani cell phone users have until midnight Thursday to register their SIM cards, or their service will be cut off. While some privacy experts worry about government intrusion, many Pakistanis are just worried about keeping their phone lines open. VOA Deewa reporter Arshad Muhmand has more from Peshawar.
Video

Video Myanmar Warns Factory Workers to End Strikes

Outside Myanmar's main city Yangon, thousands of workers walked off their jobs earlier this month demanding a doubling of their wages, pay raises after a year and input from labor unions on industrial regulations. Since Friday, the standoff has grown more tense as police moved in to disrupt the sit-ins, resulting in clashes that injured people from both sides. VOA correspondent Steve Herman visited industrial zones which have become a focus of Myanmar's fledgling workers rights movement.
Video

Video Oscar Winners Do More Than Thank the Academy

The Academy Awards presentation is Hollywood’s night to reward the best movies from the previous year. It’s typically a lot of glitter, a lot of thank you’s, a lot of speeches. But many of this year’s speeches carried messages beyond the thank you's. VOA’s Carolyn Presutti takes a look.

All About America

Circumventing Censorship

An Internet Primer for Healthy Web Habits

As surveillance and censoring technologies advance, so, too, do new tools for your computer or mobile device that help protect your privacy and break through Internet censorship.
More