Lexi Walls is a graduate student in Biochemistry. She utilizes microscopes to visualize the infection machinery of viruses at the nanoscopic level. These viral snapshots will improve our understanding of how viruses function and how best to inhibit their infection.
Do you know anyone who has been infected with smallpox? What about someone who has been paralyzed from polio? The ‘yes’ answer to these questions has recently become rare with the global eradication of small pox and the near elimination of polio, with only 22 cases in 20171. These two viral diseases and many others have been significantly reduced in the human population due to the large public health success of vaccines. Vaccines are training wheels for our immune system, allowing our bodies to practice so we can be prepared when true infection occurs. Much like the first viral encounter without a vaccine primer will result in infection, hopping onto a bicycle without ever practicing the balance and coordination required will result in many falls, scraped knees, and bruised elbows.
The first vaccine was demonstrated over 200 years ago2 and has paved the way for more than 60 FDA approved vaccines today 3,4. One question that remains is why the current methods for vaccination do not work for all viruses? This shows that significant research towards viruses, vaccines, and immune responses is still required. There are many examples of the challenges of vaccination (the recent and retracted Dengue vaccination campaign in the Philippines is a fascinating look at how complex Dengue virus is and why vaccination is such a challenge5,6), but I will focus on a virus that nearly everyone has had the ‘pleasure’ of interacting with: influenza. Influenza is one of the more characterized viruses in recent history; however, there is still no universal vaccine. One driving force behind this is the ability for influenza to revamp itself each year. Imagine that you practiced riding a bicycle with training wheels, but then were presented with a unicycle. This lack of preparation ultimately leads to failure, and is what happens to the immune system when it has not been properly prepared for each variety of influenza virus. From the viral perspective, this ability to disguise itself is imperative for successful infection and spread; however, from the vaccine perspective, this is a sizable challenge requiring annual prediction of the influenza disguise and yearly production of updated vaccines.
The current yearly influenza vaccine targets two external appendages of the virus that can exist in many different combinations and forms. The current vaccines are efficacious, but only when properly predicted and successfully produced to mimic how those appendages appear to the immune system during a true infection. To circumvent the near infinite combinations of influenza vaccines and immune system training regiments, new vaccination platforms are being explored for influenza and other difficult and currently untreatable and uncontrolled viruses. One such example for influenza is Vaccitech’s MVA-NP+M1 vaccine that is currently in clinical trials.7 The goal of this vaccine is twofold and takes a fresh approach on influenza vaccines. First, the vaccine targets two different pieces of the influenza virus that are less able to disguise themselves compared to the current influenza vaccine targets. This would therefore allow more stable protection against the influenza virus from year to year. Second, the vaccine also includes an immune system booster to stimulate a stronger and more potent response than previous vaccine efforts, giving broader and longer lasting immune defenses. This is just one example of innovation in vaccine design that could start a revolution in influenza vaccine efforts, but also other difficult and currently untreatable viral diseases.
Vaccines have been a significant and successful public health effort to reduce mortality and sickness across the world in modern times. While these have been successful, unfortunately not all viral diseases have vaccine strategies available. Currently, with motivation to better understand both the immune system and viral infection, new vaccine discovery efforts are underway for a variety of viruses, including influenza.
2 Riedel, S. Edward Jenner and the history of smallpox and vaccination. Proc (Bayl Univ Med Cent). 2005.