Supported by a federal contract, Saint Louis University will study a concept for a universal flu vaccine that is designed to protect people from influenza pandemics that could turn deadly as well as seasonal flu caused by the influenza A virus.
The National Institute of Allergy and Infectious Diseases (NIAID), which is part of the National Institutes of Health, selected SLU to work on the flu vaccine project, which has a total funding of $1.1 million.
"The ultimate aim of a universal influenza vaccine is to provide protection against all strains of influenza A viruses for many years without the need for annual vaccine strain changes or annual vaccinations," said Daniel Hoft, M.D., Ph.D., principal investigator of SLU's Vaccine and Treatment Evaluation Unit (VTEU) and director of the division of infectious diseases at Saint Louis University.
"While it is likely that we will need to take many steps to reach this goal, our proposed clinical trial will be the first test of its kind in humans and could be a huge step forward if it proves to be safe and effective."
Sharon Frey, M.D., professor of infectious diseases and clinical director of SLU's VTEU, is the prinicipal investigator on the study, and Robert Belshe, M.D., professor emeritus of infectious diseases, is the laboratory principal investigator.
Two types of flu virus - A and B - cause severe upper respiratory flu symptoms in people. SLU will design and conduct a human study of a flu vaccine approach that has worked in animal models to protect against multiple strains of influenza A, which is the type of flu that can develop into a pandemic. A global outbreak of disease, pandemic flu can cause more severe symptoms and higher death rates than seasonal flu because it comes from a new influenza virus for which people have no built in immunity.
Multiple subtypes of influenza A can affect both birds and humans, and have the potential of turning into a pandemic by quickly mutating to jump from bird to human species. They can turn deadly because people have no built in immunity against the disease and preparing a vaccine could take months, meaning the pandemic can rage before protection is available.
Influenza virus is spread when hemagglutinin proteins, which are found on the surface of flu viruses, stick to cells in the upper respiratory tract to cause infection. Hemagglutinin proteins are made up of two components: a head and a stalk.
SLU will examine a vaccine made from two different engineered hemagglutinin proteins. While both have the same H1 stalk, which is found in about half of all human influenza A viruses, their heads are from two different types of bird flu. The compound that is given to prime the immune system has a H5 avian flu head and H1 stalk and the other, which is given to boost the immune system, has a H8 head and the same H1 stalk.
"Most of us haven't seen H5 or H8 before and have no immune memory response or pre-existing immunity to the bird flu," Hoft said. "By changing the head and having a common stalk region, we can give repeated immunizations and induce minimal immune responses to the head while inducing antibodies to the stalk that are predicted to provide broader protection and possibly even longer duration of protection against influenza.
"The chimeric hemagglutinin vaccine approach we plan to study has worked in mice and ferrets to induce broadly protecting antibodies against diverse influenza A viruses, and our goal is to see if ultimately it can protect people against changing flu strains."
Hoft said influenza is the most significant health problem that many families will face in a typical winter, and called development of a universal influenza vaccine a high priority.
"Annual influenza vaccine is a costly burden on our healthcare system. Unlike other vaccines, which last for decades or even a lifetime, we need to improve the longevity of protection against influenza," Hoft said.
"Despite the many improvements we've seen to flu vaccines, vaccine is sometimes mismatched to one or more circulating seasonal strains, and the current year is a good example of this. Improved influenza vaccines are needed with broader protection."
The NIH award will cover study protocol development, clinical trial implementation and completion and detailed laboratory work that investigates the ability of the vaccine to induce an immune response.
SLU is eligible to conduct the research because its Vaccine and Treatment Evaluation Unit is one of nine elite institutions selected in 2013 by the National Institutes of Health to study vaccines of the future that will protect people from infectious diseases and emerging threats.
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