By Zyara Morton, C2ST Intern, University of Illinois Urbana-Champaign

The holiday season can bring to mind many traditions. Maybe after Thanksgiving dinner, your family watches a movie or begins setting up the Christmas tree. Or maybe as the temperatures drop and snow starts to fall, you put on your mittens and boots, and make your way straight to the pharmacy for your yearly flu shot! While less ‘festive’ than these other traditions, it is still very important to protect yourself against the flu, especially as the holiday season kicks in. However, why are we urged to receive these shots every year, around the same time? In this blog post, we will dive deeper into why yearly flu shots are necessary, and the search for a universal flu vaccine.

Influenza, commonly known as the flu, is a respiratory illness that can infect the lungs, throat, and nose. If you have ever been sick with the flu, you are probably familiar with some of the symptoms: nasal congestion, a sore throat, and even muscle weakness. Similarly to other viruses, the flu is contagious, and its effects can range from mild to severe. While influenza can be managed through various practices–such as hand washing and social distancing–one of the primary forms of protection is through repeated, yearly vaccination. These vaccinations help your body build up immunity to the disease so that if infection does occur, your body is adequately prepared to protect you. 

However, the flu is complicated. Influenza is separated into letter-based subtypes: A, B, C, and D. In humans, influenza A and B are the most prevalent, and have been responsible for various pandemics throughout history. These viruses are also seasonal, and in the USA, the peak seasons for flu are fall and winter. What makes influenza viruses even more complicated is that if two versions of the virus infect one host, they can swap genetic information with one another, and create new, unique flu variants. This constant creation of new versions of influenza requires researchers to develop a new influenza vaccine every year to keep up with these changes. This, alongside the seasonal peaks in the virus, is why it has become a sort of necessary ‘tradition’ to receive flu shots every year.  

Developing new vaccines every year can be time-consuming, and requires a lot of funding for biomedical researchers. That is why in recent years, there has been a major push towards the creation of a universal vaccine against the flu. Ideal candidates for this vaccine would protect individuals against any, and all variants of influenza, and be given less frequently than once a year. Achieving this would be tremendous in medicine, and ensure the health of millions. So then, how close are scientists to actually achieving this goal? 

In August of this year, researchers at Cleveland Clinic’s Lerner Research Institute proposed a potential candidate for a universal flu vaccine that proved to be effective in animals and provided stronger immune responses against infection after exposure. These new advancements build off of previous work, and utilize a methodology known as COBRA–Computationally Optimized Broadly Reactive Antigens. Put simply, this method analyzes the genetic sequences of different types of flu and then identifies which amino acids are the same across them. The amino acids identified make up the proteins found on the exterior of influenza viruses–which is how they infect us. Through this technique, researchers were able to look at eight different proteins associated with increased immune responses—a needed component for a universal vaccine. When this vaccine was injected into the nasal cavity of mice, their blood was found to possess antibodies four weeks later, and when infected with the virus, the mice were protected. This new vaccine has proteins from already well known strains in humans, alongside strains that humans do not have antibodies against. The researchers leading the study are looking towards launching clinical trials in one to three years, and have hopes that it can last multiple seasons and adequately protect individuals against multiple strains of the flu. 

These new developments muster a feeling of hope for the future of developing a universal vaccine against influenza. If this vaccine were to be created, it would be monumental in its benefits for humans. However, until then, cut your turkeys, stuff your stockings, and go get that seasonal flu shot—it is tradition after all! 

References

1. About Influenza
2. Types of Influenza Viruses
3. Flu Season
4. Flu shot: Your best bet for avoiding influenza
5. Universal Flu Vaccine Candidate Protects Against Infection in Mice