A universal, one-dose flu vaccine has long been a holy grail for medical researchers. With the World Health Organization estimating over half a million people die every year from influenza, and the social and economic costs being almost impossible to calculate, the impact of an effective flu vaccine cannot be underestimated. New research from the University of Washington School of Medicine could pave the way for a universal flu shot by developing a novel DNA vaccine that targets the genetic components of the virus.

"Relatively speaking, DNA vaccination is the new kid on the block with regard to the types of vaccines," explains Deborah Fuller, whose UW Medicine lab is leading this innovative research.

DNA vaccines are at the vanguard of modern medical research. Unlike conventional vaccines, which utilize whole forms of an organism to generate an immune response, a DNA vaccine inserts a genetic code into a cell directing it to produce a pathogenic antigen that subsequently triggers an immune response.

"We've been working essentially with the same vaccine (techniques) over the last 40 years," says Fuller. "It's been a shake-and-bake vaccine: You produce the virus, you kill the virus, you inject it. Now it's time for vaccines to go through an overhaul, and this includes the influenza vaccine."

DNA vaccines offer many significant benefits over traditional vaccines. They are cheaper and faster to make than current vaccine production methods and, because they target fundamental genetic components of a virus, they get around the problem of "genetic drift." This means a single shot could protect against all influenza strains, both in the past and the future.

However, early studies with DNA vaccines have not proven to be exceptionally effective, with researchers struggling to evoke strong immune responses in human subjects using the technique. Recent advances in delivery methods have reinvigorated the field, revealing that dermal skin patches can induce better antibody responses than more traditional intramuscular injections.

This latest DNA vaccine experiment for influenza has been showing positive results in its initial animal studies. The new vaccine contains DNA coding for proteins from four different flu strains, plus an extra protein considered to be more universally shared across all flu strains. Excitingly, the results suggested that a strong immune response was triggered in the animals when they were exposed to not only the four specific flu strains but also other different flu strains, meaning the vaccine had a broader universal effect.

"With the immunized groups, we found that using this conserved component of the virus gave them 100 percent protection against a previous circulating influenza virus that didn't match the vaccine," explains Fuller. "This was very exciting for us."

It is still early days in the world of DNA vaccine research, with no real human, commercial results to be expected for at least five or 10 years, but this certainly has the potential to be truly revolutionary. One of the great human achievements of the last century was the development of vaccines that have saved the lives of millions of people, from the virtual eradication of polio to the decimation of measles. DNA vaccines could be the new frontier for 21st century vaccinations, promising a whole new wave of protections from harmful infections.

The new research was published in the journal PLOS One.

Source: UW Medicine