2001 Public Health Symposium

Honoring John Maassab

Dr. John F. Maassab Dr. "John" Hunein F. Maassab received a B.A. degree in Biology and an M.A. degree in Physiology and Pharmacology from the University of Missouri. He earned a M.P.H. and Ph.D. in Epidemiology from the University of Michigan. He has been a Professor in the Department of Epidemiology at the University of Michigan since 1960 and served as the chairman from 1991-1997. He founded and directs the Hospital and Molecular Epidemiology program in the Department of Epidemiology. Dr. Maassab is a member of several scientific organizations including the American Public Health Association and the American Society of Microbiology and is a Fellow of the American Academy of Microbiology. Dr. Maassab has over 170 publications that range from studies on the basic biology of viruses to research on the development of methods to control viral infections.

Recently, Dr. Maassab was awarded patents for the development of a cold-adapted influenza virus and for an attenuated respiratory syncytial virus. Dr. Maassab received the 1997 Award for Science and Technology from Popular Science for the development of the cold-adapted influenza virus. This discovery led him to develop a flu vaccine that can be administered by a nasal spray as an alternative to the "flu shot."

Influenza and Its Prevention

Influenza, commonly called "the flu," is an infection of the respiratory tract caused by the influenza virus. Compared with most other viral respiratory infections, such as the common cold, influenza infection often causes a more severe illness. Most people who get the flu recover completely in one to two weeks, but some people develop serious and potentially life-threatening medical complications, such as pneumonia. Between 25-50 million people in the United States are infected each year with the influenza virus. In an average year, infection with influenza virus is associated with 20,000 deaths nationwide and more than 100,000 hospitalizations. Approximately 90 million workdays are lost and 30 million school days are missed each year as a result of influenza.

Vaccination can prevent disease caused by influenza. Unlike vaccines used against other viruses such as measles, mumps, rubella and varicella, people need to be vaccinated annually against influenza. This is because the influenza virus often changes its genetic composition to evade the immune system of its host. Thus, people are susceptible to influenza virus infection throughout life. The current vaccine used for flu is a "killed" virus vaccine that is administered by injection. The Centers for Disease Control and Prevention recommends a flu shot for healthy adults over age 50 and high-risk children and adults. Unfortunately, less than one percent of healthy children and less than 30 percent of healthy adults, are routinely vaccinated. Achieving adequate flu protection is difficult because each year a new vaccine must be developed that is appropriate for the specific strainsof influenza likely to circulate. Currently, there is concern n the public health community regarding the timely supply of vaccine for the coming flu season.

Dr. Maassab's Contributions to Prevention of Influenza

In 1967, Dr. Maassab published a paper in the journal Nature describing the adaptation of an influenza virus for growth at a low temperature in culture. Importantly, this "cold-adapted" virus does not grow at higher temperatures such as those found in the lungs. However, the cold-adapted virus can replicate in the nasal passages where the temperature is lower. The cold-adapted virus cannot survive in the lungs where the body temperature is higher, and therefore cannot cause disease. The limited viral growth seen in the nasal passages may stimulate an immune response that may protect a person from infections from influenza viruses. This protection also prevents the spread of influenza to others.

Dr. Maassab developed an intranasal cold-adapted live virus vaccine that may provide promising alternative to the "flu shot." Using a nasal mist, an attenuated (weakened) live form of the influenza virus is sprayed into the nasal passages, where influenza viruses enter the body.

The public health significance of this finding for the development of an influenza vaccine is apparent. By using nasal mist technology to eliminate the fear of injections, this method may offer the first practical way to immunize children and adults on a large scale annually in the near future.

The use of the cold-adapted influenza virus has been licensed to Aviron, a biopharmaceutical company specializing in disease prevention. Clinical trial results, published in the New England Journal of Medicine, Journal of the American Medical Association, The Journal of Pediatrics and The Journal of Infectious Diseases suggests that the cold-adapted vaccine (FluMist™) provided greater than 90 percent protection against influenza infection in healthy children ages one to six years old. Additionally, the children receiving the vaccine had 30 percent fewer ear infections with fever and a 35 percent reduction in related antibiotic use for ear infections. Clinical trials indicate that FluMist™ is well tolerated and effective in both children and adults. Data from clinical trials of FluMist™ in adults has also indicated effectiveness in reducing illness-associated missed workdays, health care provider visits and medication use associated with illness.

The culmination of a lifetime study of the influenza virus by Dr. Maassab has the potential to result in the reduction of influenza morbidity and mortality worldwide. Along with his wife Hilda, Dr. Maassab also has contributed identical twin sons.