Understanding about key flu protein could help with universal vaccine

Improved understanding of the structure of a key influenza virus surface protein could result in a new vaccine target, according to research recently published in the Proceedings of the National Academy of Sciences.

Researchers with the Stanford School of Engineering focused on creating a fragment of the flu vaccine's protein stem that could be injected into the bloodstream to create an antigen for the immune system. While today's vaccines are based on inactivated viruses containing the heads of hemagglutinin proteins, the head can change from year to year while the stem remains more constant over time. A vaccine targeting the stem of the flu virus could result in a universal flu vaccine.

The researchers used an experimental process called cell free protein synthesis to recreate the protein stem of the H1N1 virus that caused the flu pandemic of 1918. After dozens of tries over two years, the researchers were able to create a viral stem protein that could serve as a good antigen.

"This has been a tough process," James Swartz, the leader of the research team, said. "Many labs have been trying to develop an HA stem vaccine and we're glad to have made these contributions."

The next step in the process is attaching the stem protein to a virus-like particle in an effort to create a stronger immune system response. If that step is successful, the vaccine candidate could undergo safety and efficacy trials in animals, and later, in humans.

"This is an important project for world health," Swartz said. "These are big challenges but we are committed to the effort."

According to recent estimates, flu-related illnesses kill between 250,000 and 500,000 people annually throughout the world.