The promise of prevention
The ebola epidemic that began last year in West Africa has killed more than 11,000 people and led to horrible suffering and worldwide apprehension and fear. So TWAS Fellow Vincent Titanji of Cameroon was excited by the recent study of a new vaccine that appears extremely effective against the virus, but he also saw it as a signal on how to improve Africa's struggling health systems.
The trial for the vaccine, called rVSV-ZEBOV, was conducted in an area of Guinea where ebola was actively infecting people. The vaccine protected from ebola every single one of the 4,123 Guineans who received it immediately at the beginning of the trial, according to a study in The Lancet. In the same trial, 16 out of 3,528 Guineans who received the vaccine only after a three-week delay became sick with ebola. That indicates that the vaccine is 100% effective, which is very rare. On top of that, it worked quickly and had few side effects. Health workers are now planning a second, bigger trial in which every participant will immediately receive the vaccine.
“When the epidemic erupted, all of us were looking forward to a day when we would have such a tool in our hands to control this dreadful disease,” said Titanji, a prominent African epidemiologist at the University of Buea in Cameroon. Titanji, a 2004 TWAS Fellow, has worked extensively on helping control infectious diseases in Africa, including river blindness, tuberculosis and malaria. Even though the ebola outbreak did not reach Cameroon, it was still a major concern in the country because of the strong possibility it could be spread by a traveler from a nearby country, such as Sierra Leone, Liberia or Guinea, where health workers are still actively fighting the disease.
But just as important as the good news, he said, there are lessons that Africa and the rest of the world can draw from it about the importance of vaccines and researchers working with communities.
Titanji said the speed at which the vaccine was developed was a reflection of how much progress has been made in the science of immunology, and he hopes the apparent success of the ebola vaccine will lead to further vaccine development for other infectious scourges. But he said medical scientists and health administrators should not react to disease outbreaks so much as anticipate that they may happen – and be better-prepared when they do. After all, how many lives might have been saved had the vaccines been available sooner?
“It’s a very highly infectious viral disease and it’s just sufficient for one person to travel out of the endemic zone to start a whole infection in a new location,” said Titanji. With ebola, he added, “I think the funders felt equally as threatened as those who were in the developing area. Nevertheless the lessons are very clear: If we prioritize these conditions and resources and concentrate them, and there is synergy of action, then I think we can get better results.”
In Sub-Saharan Africa, he said, many countries give in to the temptation to imitate the North by focusing their health systems on the expensive, curative kinds of medicine that dominate developed countries. But building health centres and pharmacies don’t solve a country’s most pressing needs when it’s staring down a threat from perfectly preventable, neglected tropical diseases. It’s important to instead focus on developing and distributing the preventative tools, as well as water and sanitation.
Titanji has been working on such a preventative measure, a vaccine for malaria. The disease killed about half a million people worldwide in 2013, mostly in sub-Saharan Africa. But scientists have been working on a vaccine for malaria for decades and it’s proven to be a frustrating task. None of the vaccines, even the one most furthest along called RTS,S, which was approved for use in Africa in July, have showed the results at the level the ebola vaccine did.
But vaccines are far from the only option. There are programmes that can distribute bed nets and destroy mosquito habitats before the disease gets out of control. Concentrated efforts can eliminate malaria from a region, an accomplishment achieved by developed countries and even some African island countries like Mauritius and Seychelles.
The key is to involve everyone in the preventative efforts, from drug companies to researchers to local communities that can help on the ground.
“Health planners, the governments, multilateral organizations – I think we need to put all this expertise together to design and customize health systems that can take care of prevention,” Titanji said. “Involve the communities so we can look inside their health. And then channel the resources that are available.”
Communities have also been critical to controlling the ebola crisis by helping people discourage behaviour that could spread the disease locally, such as shaking hands. Communities have also helped distribute drugs for treating the symptoms of diseases like river blindness.
“One of the things the ebola epidemic...taught us," he said, "is that when you concentrate various efforts together and have strong leadership and have resources put in place and the best science focused on the problem, you usually have better and quicker results to control the disease.”