Influenza kills between 290,000 and 650,000 people annually, according to the World Health Organization. And major pandemics are capable of causing millions of deaths across the globe, much like the Spanish flu outbreak of 1918, which was responsible for an estimated 30 to 50 million deaths worldwide.
Existing vaccines for the flu are effective, but not perfect. They rely on antibodies to fight the infection, but they only target the surface characteristics, which doesn’t stop the virus from adapting and mutating — thus more devious strains develop, creating the need to constantly create and administer upgraded vaccines.
But researchers are working on a universal flu vaccine as a possible solution.
Recently, the National Institute of Allergy and Infectious Diseases (NIAID) opened the Collaborative Influenza Vaccine Innovation Centers (CIVICs) program, a network of research centers that will work collaboratively to develop longer-lasting, more broadly protective flu vaccines. Researchers from the University of Georgia, Duke University, the University of Maryland School of Medicine and the Icahn School of Medicine at Mount Sinai will work together, sharing approximately $51 million in first-year funding, which is designed to support the program for seven years.
“To more effectively fight influenza on a global scale, we need better influenza vaccines that are more broadly protective,” said NIAID Director Anthony S. Fauci, M.D. in a statement. “With the CIVICs program we hope to encourage an exchange of ideas, technology and scientific results across multiple institutions to facilitate a more efficient and coordinated approach to novel influenza vaccine development.”
Researchers at the University of Georgia developed a vaccine with nanoparticles that is double-layered because it combines two major influenza proteins. Mice that were given the vaccine were found to be protected against six different influenza viruses. The results, which were published in Advanced Healthcare Materials, suggest the combination has potential as a universal flu vaccine.
“This nanoparticle antigen combination conferred mice with strong cross protection,” study author Ye Wang, a biology Ph.D. student, said in a statement. “It can protect mice from different strains of influenza virus. Each season, we have different flu strains that affect us. By using this approach, we hope this nanoparticle vaccine can protect humans from different strains of influenza virus.”
Researchers at the University of Nebraska-Lincoln also have been trying to develop a universal flu vaccine. Their vaccine combines ancestral genes from four major influenza strains and "appears to provide broad protection against the flu," according to a study published in the journal Scientific Reports.
Researchers gave mice their new vaccine and then exposed them to lethal doses of various flu viruses. But all the mice survived. In comparison, mice that received the current flu vaccine all got sick or died.
"The ultimate goal is to be able to vaccinate once and provide lifelong protection," lead researcher Eric Weaver, an assistant professor in the School of Biological Sciences at the University of Nebraska-Lincoln, said in a statement. "Our current influenza vaccine programs and technologies reduce influenza infections and hospitalizations by 4.75 percent and 6.9 percent, respectively. There is no doubt that there is a need for more effective vaccine technologies."
Another approach to the universal vaccine
In 2013, researchers discovered a “blueprint” for a universal vaccine that could protect against all strains of seasonal influenza, and remarkably, even future viruses that are as yet unknown.
During the 2009 swine flu pandemic, scientists monitored the health condition of more than 300 students and staff at the Imperial College London. They discovered that people who were minimally affected by the flu had a stronger presence of CD8 T cells in their blood at the start of the pandemic; CD8 T cells are naturally occurring immune cells the body uses to fight viruses.
Professor Ajit Lalvani, from the National Heart and Lung Institute at Imperial College London, who led the study, said that a vaccine that made the body produce more of these cells had the potential to be “the holy grail” and could offer a universal vaccine effective against all strains of flu.
“The immune system produces these CD8 T cells in response to usual seasonal flu,” Lalvani said. “Unlike antibodies, they target the core of the virus, which doesn’t change, even in new pandemic strains. The 2009 pandemic provided a unique natural experiment to test whether T cells could recognize, and protect us against, new strains that we haven’t encountered before and to which we lack antibodies,” reports The Independent.
“We already know how to stimulate the immune system to make CD8 T cells by vaccination. … Now that we know these T cells may protect, we can design a vaccine to prevent people getting symptoms and transmitting infection to others,” Lalvani added. “This could curb seasonal flu annually and protect people against future pandemics.”
The results were published in the journal Nature Medicine.
Editor's note: This story has been updated with new information since it was originally published in September 2013.