The World Health Organization has warned that a global influenza pandemic remains a real threat despite progress made over the past 10 years in increasing the worldwide supply of flu vaccines.
In 2006, the World Health Organization acknowledged that countries around the world were ill-prepared to tackle an influenza pandemic. At the time, there were concerns about an H5N1 bird flu pandemic spreading globally.
In response, the WHO launched the Global Action Plan (GAP) for influenza vaccines with three main objectives. It aimed to increase evidence-based seasonal vaccine use; increase vaccine production as a protection against pandemics and improve regulatory capacity in developing countries; and promote research and development for better vaccines.
That initiative has now ended, but Marie-Paule Kieny, WHO assistant-director general for health systems and innovation, observed that global preparation for an influenza pandemic had vastly improved over the past decade.
"We are certainly better prepared for an influenza pandemic than we were 10 years ago," Kieny said, "but,we must not lose the momentum and we are still facing the threat of an influenza pandemic in 2016."
More vaccine production
The WHO said global production capacity for pandemic vaccines increased from an estimated 1.5 billion doses in 2006 to 6.2 billion last year. While it's an impressive achievement, Kieny said, it "still falls short of the GAP goal to immunize 70 percent of the population with two doses of vaccine, potentially for which we would need 10 billion doses."
She noted that only rich countries were producing vaccines in 2006, whereas today, 14 mostly upper-middle-income countries were making strides toward manufacturing their own vaccines.
In addition, she said, the number of countries that have national influenza immunization policies in place has increased from 74 to 115 today, "including lower-middle-income countries and one low-income country."
William Ampofo, a professor at the University of Ghana and an advisory group member of the GAP, said he was encouraged by the progress made, but he told VOA he was disappointed that the creation of the GAP had not resulted in increased vaccine production capacity in Africa.
"As part of the GAP, technology transfer was provided for developing countries, and South Africa and Egypt were part of this initiative," he said. "Unfortunately, the tech transfer has not resulted in influenza vaccine production capacity as of now."
He added, however, that the Ebola epidemic in West Africa had shown that vaccination is an effective tool against a dangerous virus and that the manufacture of a flu vaccine on the continent should be seriously considered.
"Because of what happened with Ebola, now the countries — in West Africa, especially — the ministers of health are now giving attention to vaccine production capacity on the African continent," he said. "They recognize, however, that it is very difficult, but they feel that something must be started."
The flu season in the Northern Hemisphere is set to start in December, peak in late January or early February and run its course by April or May. The WHO estimates every year there are between 3 million and 5 million forensic cases of influenza, resulting in 150,000 to 500,000 deaths.
A large variety of viruses or subtype influenza viruses are circulating in wild and domestic birds. Only three viruses currently are circulating in humans: influenza A (H1N1), an influenza A variant (H3N2) and an influenza B virus. Traditional flu vaccines, called "trivalent" vaccines, are made to protect against those three flu viruses.
Wenqing Zhang, a scientist in WHO's Department of Pandemic and Epidemic Diseases, said the influenza viruses are constantly changing. She said one type of change, "antigenic drift," results in small changes in the genes of influenza viruses. A second way, "antigenic shift," involves an abrupt, major change.
"With the antigenic drift, it will cause an epidemic, and if there is an antigenic shift, then there will be a pandemic," she said. "Because the virus is constantly evolving, the threat of influenza pandemic is real. It is very real. It could be tomorrow or in five years' time. It could be mild like the 2009 H1N1 pandemic, or it could be a very severe one, like in 1918."
During the 1920s, scientists estimated that 21.5 million people had died as a result of the 1918-19 influenza pandemic. More recent estimates have put the death toll at between 50 million and 100 million.