FDA approves nasal spray flu vaccine invented at U-M

Maassab in his lab

ANN ARBOR, Mich.—The FDA’s approval of a new nasal spray flu vaccine brings to fruition four decades of research by a University of Michigan professor.

The U.S. Food and Drug Administration today approved FluMist, based on technology developed by Hunein “John” Maassab, emeritus professor of epidemiology at the U-M School of Public Health. FluMist is approved for use by healthy people ages 5-49.

“I feel good. I feel in a sense that I have accomplished my life’s dream,” Maassab said. “I spent all my lifetime developing this vaccine.”

FluMist is a cold-adapted, live-attenuated, trivalent influenza virus vaccine. It is the only influenza vaccine delivered as a nasal mist to be commercially available in the United States. MedImmune Vaccines Inc., a wholly owned subsidiary of MedImmune Inc. (Nasdaq: MEDI), will manufacture and market FluMist, and Wyeth Vaccines, a business unit within Wyeth (NYSE:WYE) will co-market it. MedImmune has announced its plan to have FluMist available in time for this year’s flu season.

Maassab began work on an influenza vaccine in the 1950s as a public health graduate student under the direction of Dr. Thomas Francis Jr.—the researcher credited with first isolating flu virus and with developing the first killed virus flu vaccine, and perhaps best known as the scientist who announced to the world that the Jonas Salk polio vaccine was safe and effective. Francis supervised the U.S. Army's flu vaccine program during World War II, and later asked Maassab to focus on a live virus vaccine.

Maassab first isolated the influenza type A-Ann Arbor virus in 1960, and in 1967, he published a landmark paper in the journal Nature describing the adaptation of an influenza virus for growth at a low temperature in culture. That was an influenza A strain.

For the next several decades, he worked to develop a B strain, as well as to find the technology to re-engineer new vaccine lots with each year's flu strain. He continued to work into the late 1990s to learn more about the molecular basis of the attenuation of cold-adapted viruses.
Asked why he spent his entire career focused on flu, Maassab said matter-of-factly: “The initial work was very positive and with that, I continued. If it wasn’t positive initially, I would have done something else.”

The Centers for Disease Control and Prevention estimates each year about 114,000 people in the United States are hospitalized and about 20,000 people die because of flu.

FluMist uses a live but weakened virus, administered to help develop immunity. This weakened virus is adapted to grow at the lower temperatures of the nasal passages but not the warmer conditions of the lungs where influenza disease develops. A trivalent vaccine, like the flu shot, it includes three different strains of vaccine.

Video:

Click on these video clips to see John Maassab discuss his career and FluMist.

Video 1 | Video 2 | Video 3 | Video 4 | Video 5