The U.S. medical scientist who led a team that helped eradicate outbreaks of smallpox in the 1970s says the global community is now more responsive to possible pandemics despite challenges posed by viruses such as AIDS, bird flu and more recently Ebola.
Scientist Donald Henderson was recognized for his contributions to public health at a time of growing concern over public opposition to vaccination programs.
Henderson, dean emeritus at the Bloomberg School of Public Health at John Hopkins University, is no stranger to battling life threatening viruses after leading the World Health Organization (WHO) team in the 1970s to eradicate smallpox.
The campaign’s success, with the WHO declaring in May 1980 that smallpox had been eradicated, came after as many as 500 million deaths from the disease in the 20th century.
Nearly 25 years later, population growth and the greater ease of global travel has elevated the risk to communities from viruses able to be transmitted across borders.
But Henderson said the outbreaks have had a positive impact of putting global health systems on alert.
“The one thing that’s encouraging, and I shouldn’t put it that way, but we have enough organisms out there, enough movement - enough outbreaks that it is right now a lot easier to begin to move quickly into a problem. What we have now, which is very different from earlier days, is a willingness to share their information, a willingness to say we’ve got a problem,” he said.
But challenges remain. Henderson said AIDS is still the world’s main health threat for which there is still no vaccine.
The WHO said more than 36 million people have died since the start of the epidemic over two decades ago, with over 75 million infected with HIV - the virus that leads to AIDS. Henderson said the impetus for a vaccine is increasing.
“The treatment is not complete for anyone. They’re taking it for life. So it’s a great threat that we have right before us at this time. The number of people that require drugs is gradually increasing. We’re finding out that it’s not easy to keep these people on drugs indefinitely. That’s a problem. And the cost of this is mounting exponentially,” said Henderson.
In 2012 close to 10 million people living with HIV had access to antiretroviral therapy - the drugs which suppress the virus. Although the rates of new infections have dropped, there are still around 2 million new cases each year, including some 300,000 children.
Henderson, in Thailand to receive the country’s prestigious Prince Mahidol Award in medical research, says even the smallpox campaign had to overcome public resistance to the vaccination programs.
Despite decades of success in combatting diseases, vaccination programs are still facing an uphill battle in some places. In Pakistan and Afghanistan the battle against polio has stalled because of opposition by Islamic extremists who accuse vaccination teams of spying. In the United States, there are some who remain skeptical over the benefits of vaccinations, and suspicions they cause disease. The vaccination refusals have led to more outbreaks of the highly contagious measles virus, which was once believed to have been largely eradicated in America.
Henderson said people need to be encouraged to support vaccination. But he added new research is necessary to provide new options to support child vaccinations and ensure past gains in lowering outbreaks are sustained.
“It’s very hard to persuade, very hard to persuade people to vaccinate when they don’t have the disease. There are answers to this. That is I think if we could vaccinate with an oral vaccine - with a little patch on the skin rather than the needle and syringe which can be an emotional thing with parents,” Henderson explained.
A search for a vaccine is the latest step in the fight against the Ebola virus in West Africa. A trial of an Ebola vaccine was launched this week in the Liberian capital of Monrovia, backed by music and singing to overcome Liberians’ reluctance to accept vaccines and fears of conspiracies.
The latest Ebola outbreak, focused on the West African states of Liberia, Guinea and Sierra Leone has claimed more than 8,500 lives and infected more than 21,000 people.
Henderson said the recent disease outbreaks have helped to improve communications and encourage countries to seek international support - both hopeful signs for the future of combatting deadly outbreaks of communicable disease.