Young child gets his annual flu shot. However, scientists believe the annual flu shot could soon be a thing of the past.
PORTLAND, Ore. — The annual flu shot could soon be a thing of the past. Scientists are working on a revolutionary formula that would result in only needing one flu shot in your lifetime. Simply put, this would mean no more annual vaccinations or worrying about whether this year’s shot will match the flu strains circulating around the world.
Scientists at Oregon Health & Science University (OHSU) have developed a promising approach to creating this universal influenza vaccine — one that could provide lifelong protection against the ever-changing flu virus. Their study, published in Nature Communications, tested a new vaccine platform against H5N1, a bird flu strain considered most likely to cause the next pandemic.
Here’s where it gets interesting: instead of using the current H5N1 virus, researchers vaccinated monkeys against the infamous 1918 flu virus – the same one that caused millions of deaths worldwide over a century ago. Surprisingly, this approach showed remarkable results.
“It’s exciting because in most cases, this kind of basic science research advances the science very gradually; in 20 years, it might become something,” says senior author Jonah Sacha, Ph.D., chief of the Division of Pathobiology at OHSU’s Oregon National Primate Research Center, in a media release. “This could actually become a vaccine in five years or less.”
So, How Does This New Vaccine Work?
Unlike traditional flu shots that target the virus’s outer surface – which constantly changes – this approach focuses on the virus’s internal structure. Think of it like targeting the engine of a car instead of its paint job. The internal parts of the virus don’t change much over time, providing a stable target for our immune system.
The researchers used a clever trick to deliver this vaccine. They inserted small pieces of the target flu virus into a common herpes virus called cytomegalovirus (CMV). Don’t worry – CMV is harmless for most people and often causes no symptoms at all. This modified CMV acts like a Trojan horse, sneaking into our bodies and teaching our immune system’s T cells how to recognize and fight off flu viruses.
To test their theory, the team exposed vaccinated non-human primates to the H5N1 bird flu virus. The results were impressive: six out of 11 vaccinated animals survived exposure to one of the deadliest viruses in the world today. In contrast, all unvaccinated primates succumbed to the disease.
“Should a deadly virus such as H5N1 infect a human and ignite a pandemic, we need to quickly validate and deploy a new vaccine,” says co-corresponding author Douglas Reed, Ph.D., associate professor of immunology at the University of Pittsburgh Center for Vaccine Research.
The study tested a new vaccine platform against H5N1, a bird flu strain considered most likely to cause the next pandemic. (Photo by Felipe Caparros on Shutterstock)
What makes this approach even more exciting is its potential to work against other mutating viruses, including the one that causes COVID-19.
“For viruses of pandemic potential, it’s critical to have something like this. We set out to test influenza, but we don’t know what’s going to come next,” Dr. Sacha believes.
The success of this vaccine lies in its ability to target parts of the virus that remain consistent over time.
“It worked because the interior protein of the virus was so well preserved,” Sacha continues. “So much so, that even after almost 100 years of evolution, the virus can’t change those critically important parts of itself.”
This breakthrough isn’t just limited to flu prevention. The same vaccine platform is already being tested in clinical trials against HIV and shows promise in targeting certain cancer cells. It’s part of a broader trend in medical research that’s rapidly changing how we approach disease prevention and treatment.
“I think it means within five to 10 years, a one-and-done shot for influenza is realistic,” Sacha says. “It’s a massive sea change within our lifetimes. There is no question we are on the cusp of the next generation of how we address infectious disease.”
While there’s still work to be done before this vaccine becomes available to the public, the research represents a significant step forward in our fight against influenza and other evolving viruses.
Paper Summary
Methodology: A New Approach to Vaccination
The study hinges on a unique vaccine design that employs CMV vectors to express conserved internal proteins from the influenza virus. Unlike traditional flu vaccines that target strain-specific surface proteins prone to frequent mutations, this approach focuses on the internal components of the virus, which are far more stable across different strains. By doing so, the vaccine aims to offer protection against a wide array of influenza variants, including those potentially responsible for future pandemics.
To test their vaccine, the researchers immunized Mauritian cynomolgus macaques with their CMV-based vaccine expressing proteins from the 1918 H1N1 influenza strain. They then exposed these animals to a lethal dose of a different and highly pathogenic avian influenza virus (H5N1) through aerosolized particles, simulating a natural infection pathway.
Key Results
While all unvaccinated monkeys succumbed to the infection within seven days, showing severe respiratory distress, a significant portion of the vaccinated group survived the challenge. The survival rate among the vaccinated monkeys was over 50%, a stark contrast to the uniform fatality in the control group.
Importantly, the protection was correlated with the presence of high levels of lung-resident influenza-specific CD4+ T cells, a type of immune cell that plays a crucial role in fighting infections.
Study Limitations
Despite the encouraging results, the study acknowledges several limitations. The CMV vector-based vaccine did not prevent infection altogether; rather, it mitigated the severity of the disease and enhanced survival rates.
Moreover, the vaccine’s efficacy varied among individuals, which the researchers attribute to differences in the immune response activation across the vaccinated subjects. These variations underline the complexities of immune system interactions with such vaccines and point to the need for further optimization.
Discussion & Takeaways
The discussion section of the paper delves into the broader implications of these findings for vaccine development. The researchers highlight the potential of T cell-mediated immunity, elicited by CMV vectors, as a promising avenue for developing vaccines that can offer broad protection against diverse influenza strains and potentially other rapidly mutating viruses.
The successful use of CMV vectors in this study not only opens new doors for influenza prevention strategies but also suggests a template for tackling other diseases with similar challenges in vaccine development. Moving forward, the research team emphasizes the need for additional studies to refine the vaccine formulation and to understand the underlying mechanisms of protection more deeply, which could eventually lead to clinical trials in humans.
This breakthrough, while still in the early stages, marks a significant step toward the long-sought goal of a universal influenza vaccine, offering hope that future flu pandemics could be more effectively managed or even prevented.
Funding & Disclosures
The research was supported by the Bill & Melinda Gates Foundation Grand Challenges grant awards OPP1213553 and National Institute of Allergy And Infectious Diseases of the National Institutes of Health award R01AI40888; with support from the Office of the Director of the National Institutes of Health award P51OD011092 to the Oregon National Primate Research Center at OHSU. The findings and conclusions contained within are those of the authors and do not necessarily reflect the positions or policies of the Bill & Melinda Gates Foundation or the National Institutes of Health.
