20 VS. 4- A Universal Flu Vaccine
Every autumn, it’s the same routine: scientists predict which 4 or 5 strains of influenza will be circulating in the coming months, prepare a vaccine, and those who want it get it; sometimes the predictions are accurate, and people are spared from the virus, but other times it is not.
As we have learned in AP Biology, the human body has both innate immunity and acquired immunity to protect against diseases; vaccination is a form of artificially acquired immunity, in which a vaccine introduces the immune system to proteins from a virus; this trains the immune system to produce antibodies against the virus, so it knows how to encounter the actual virus later, should it be necessary. Unfortunately, when it comes to the flu vaccine, the antibodies that we are trained to produce from the vaccine are often not a match for the circulating flu strains, which causes the vaccine to be less effective.
But what if there were a way around this? Suppose that, instead of having to play a delicate guessing game as to which flu viruses are circulating more than others, there was a single, comprehensive vaccine that could provide immunity for multiple strains at once. This may be a real possibility in the near future; in November 2022, a research team at the University of Pennsylvania designed an influenza vaccine using mRNA technology, and when tested in mice and ferrets, was discovered to protect against 20 different strains of influenza.
One may be wondering, how could such a feat be possible? Well, we must look at how this specific vaccine was designed; it was made in a very similar fashion to the COVID-19 Pfizer and Moderna vaccines, using mRNA technology. When a person takes the Pfizer or Moderna vaccine, mRNA is introduced into the person’s body, triggering their cells to recreate a harmless version of the spike protein, causing the person’s immune system to recognize it and therefore learn how to create an efficient immune response against the virus.
The fact that this has been seen in the COVID-19 vaccine makes it easier to understand why the mRNA vaccine created for influenza was effective in mice. This is very different from the traditional influenza vaccine, which involves injecting an unactivated or weakened version of the virus into the body; while it is a formidable opponent against the influenza when the strains are a match, the design of traditional vaccines have been found to be less protective than mRNA vaccines.
The experimental 20-strain influenza vaccine has yet to undergo human trials, but it does provide some optimism looking into the future of flu seasons.