Every year, millions of people get the flu shot. Although the vaccine provides protection for many people, some people still get the flu, in part, because the influenza vaccine production cycle starts at least six months in advance of the flu season. And while the World Health Organization’s selection is based on surveillance data collected from around the world, the strains in the vaccine do not always match those actually circulating. It’s a prediction that doesn’t always hit the mark.

But thanks to advances in gene sequencing, gene synthesis and other technologies, scientists are working to develop RNA vaccines, which have the potential to allow faster and more effective responses to infectious disease outbreaks, such as the seasonal flu. “If these technologies and processes are successfully developed, vaccines could be produced more quickly, more reliably, and using more standardized methods,” says Phil Dormitzer, Vice President and Chief Scientific Officer for Viral Vaccines at Pfizer’s Pearl River, N.Y. research and development site.

Vaccines are considered one of the greatest developments of modern medicine, helping to nearly wipe out many infectious diseases. But creating and developing vaccines involves a long and complex process that remains a combination of art and science.

Many standard vaccines work by injecting a dead or weakened form of the pathogen into the body in preparations that are designed not to make you sick but rather to build immunity. The key to building this immunity is that the portion of the pathogen called the antigen trains the immune system to recognize and respond to the infectious agent. RNA vaccines, however, could be a game-changing approach to building immunity. RNA vaccines work by introducing into the body a messenger RNA (mRNA) sequence that contains the genetic instructions for the vaccinated person’s own cells to produce the vaccine antigens and generate a strong immune response.

As we enter flu season, read on to learn more.