The Hunt For A Universal Flu Vaccine – Current Happenings Across STEM Magazine

What new studies and research mean for the future of fighting the flu

Every year, 175 million Americans line up at their local pharmacy, waiting to get a shot they hope can protect them from a fever, cough, and runny nose: the most common symptoms of the flu (1). According to the World Health Organization, the influenza virus infects almost one billion people worldwide yearly, causing 290,000 to 650,000 deaths annually (2). This relentless cycle strains our hospitals each winter and affects our daily lives.

Since the development of the first influenza vaccine in the early 1940s, scientists have constantly tried to remain a step ahead of the virus (3). The rapidly changing nature of the influenza virus means that each year, scientists must analyze and predict which strains of influenza will have the most impact and formulate a vaccine to protect against those strains (1, 3). These vaccines usually protect against four strains of influenza that scientists pick out of over 130 subtypes each year. They work by training the body’s immune system on inactive versions of the virus: producing antibodies and making the body more effective against live versions of the virus (1). However, even with the expertise of the world’s best doctors and scientists, with only protection against four different strains of influenza, not every case of influenza can be prevented. This is why many scientists are aiming to develop a universal flu vaccine, which would be capable of targeting many more strains of influenza and providing more complete and long-lasting protection against the virus (4).

A diagram depicting different parts of an influenza virus.

Currently, at least 218 separate universal flu vaccines are in development, with 166 separate developers and 40 vaccines in clinical testing. Each of these vaccines is being studied for its potential to provide broader protection against influenza than the current seasonal vaccines (5). Scientists are using a host of both new and old technologies, including influenza-based, nucleic-acid-based, nanoparticle-based, recombinant protein-based, viral particle-based, or viral vector-based technologies, to maximize the chance of achieving a breakthrough (5).

One promising approach to creating a universal flu vaccine is targeting a part of the influenza virus that does not easily mutate (6, 7). Current flu vaccines target proteins on the outside of the virus. However, these proteins change quickly, rendering the vaccine useless if the virus mutates (6, 7). Dr. Luis Martinez Sobrido at the Texas Biomedical Research Institute and his team have worked to isolate antibodies that can target the slow-changing parts of the virus and to test their effectiveness in animals. Dr. Suresh Mittal is developing a vaccine to target a nucleoprotein inside the virus that stays constant throughout many strains. He aims to neutralize the virus by training T-cells in the body to recognize the virus instead of the antibodies (6, 8). Dr. Nicholas Heaton at Duke University devised a different approach, attacking the same protein that seasonal vaccines use, called hemagglutinin, but targeting the stalk of the protein instead of the easily mutating head (7).

At the National Institute of Allergy and Infectious Diseases, the Vaccine Research Center also uses hemagglutinin but aims to expand on the current seasonal vaccine technology using nanoparticle technology, mounting the protein on small nano-scaffolds. Nano-scaffolding could increase the number and variety of proteins in a singular vaccine, inducing antibodies against many different strains (9). Research on nanoparticle technology could broaden the coverage of a flu vaccine, and testing has begun on a vaccine that provides coverage against six strains of influenza instead of only four (9).

Lastly, vaccine research led by Dr. Jonah Sacha at the Oregon Health & Science University was able to successfully generate an immune response to the modern influenza H5N1 virus using fragments from the 1918 flu virus (10). Sacha and his team inserted small pieces of the influenza virus within another virus named human cytomegalovirus, a relatively harmless virus that infects most humans in their lifetime (10). The harmless virus acted as a vector, delivering the pieces of the influenza virus into the cells during their natural infection processes (10). These pieces provoked a response within immune cells named effector memory T-cells, training them to target the internal structures of influenza and not their outer shells (10). During his testing, six out of eleven primates survived, even though they were vaccinated based on a 100-year-old virus (10). Vaccines for hepatitis B, Ebola, and COVID-19 have also been developed using viral-vector technology, and a universal flu vaccine could also be developed using this technology with further research.

Influenza vaccines are typically administered with a needle into the arm.

With over two hundred vaccines in development and many exciting new technologies being explored in the hunt for a universal flu vaccine, the future of the fight against influenza looks promising. The flu continues to pose a threat to public health every fall and winter, but a universal flu vaccine could reduce the need for seasonal shots, alleviate pressure on the healthcare system, and save countless lives. Innovations in viral vectors, nanoparticle technology, and immune cell training could also revolutionize treatments and vaccines for diseases and infections other than the flu. As the flu season approaches, a breakthrough in the pursuit of a flu vaccine could make this year the last year we need an annual flu shot.

Bibliography:

CDC. (2024, September 18). Influenza (Flu). Retrieved September 29, 2024, from Centers for Disease Control and Prevention website: https://www.cdc.gov/flu/index.htm
World Health Organization. (2023, October 3). Influenza (Seasonal). Retrieved September 29, 2024, from Who.int website: https://www.who.int/news-room/fact-sheets/detail/influenza-(seasonal)
World Health Organization. (2022). History of influenza vaccination. Retrieved September 29, 2024, from Who.int website: https://www.who.int/news-room/spotlight/history-of-vaccination/history-of-influenza-vaccination
R. Nachbagauer, & Krammer, F. (2017). Universal influenza virus vaccines and therapeutic antibodies. Clinical Microbiology and Infection, 23(4), 222–228. https://doi.org/10.1016/j.cmi.2017.02.009
University of Minnesota. (2017, February 21). Universal Influenza Vaccine Technology Landscape | CIDRAP. Retrieved September 30, 2024, from CIDRAP website: https://ivr.cidrap.umn.edu/universal-influenza-vaccine-technology-landscape
American Lung Association. (2023). The Search for a Universal Flu Vaccine. Retrieved September 30, 2024, from Lung.org website: https://www.lung.org/blog/universal-flu-vaccine
Duke University. (2024). New Strategy Could Lead to Universal, Long-Lasting Flu Shot | Duke Today. Retrieved September 30, 2024, from Duke Today website: https://today.duke.edu/2024/05/new-strategy-could-lead-universal-long-lasting-flu-shot
Braz, K. (2024, March 8). Cracking the Code on a Universal Flu Vaccine. Retrieved September 30, 2024, from Purdue College of Veterinary Medicine website: https://vet.purdue.edu/news/cracking-the-code-on-a-universal-flu-vaccine.php
National Institutes of Health. (2023, September 15). NIH Clinical Trial of Universal Flu Vaccine Candidate Begins. Retrieved September 30, 2024, from National Institutes of Health (NIH) website: https://www.nih.gov/news-events/news-releases/nih-clinical-trial-universal-flu-vaccine-candidate-begins
Robinson, E. (2024). Study shows promise for a universal flu vaccine. Retrieved September 30, 2024, from OHSU News website: https://news.ohsu.edu/2024/07/19/study-shows-promise-for-a-universal-flu-vaccine

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