LINDA SAIF WORKS hard every day to improve animal health and save producers treatment time and costs. But she also works hard to save human lives.

A researcher with OARDC's Food Animal Health Research Program (FAHRP), Saif is working on the development of vaccines for the control of rotaviruses and caliciviruses — intestinal viruses that cause diarrheal diseases in young food-producing animals and human infants.

"Nearly one million children die of rotavirus diarrhea annually, especially in developing countries, but no human rotavirus vaccines are available," said Saif, who is considered a world expert on enteric viral diseases. "Commercial rotavirus vaccines for animals lack efficacy, and there are no vaccines or specific treatments for caliciviruses, the leading cause of food-borne gastroenteritis diseases."

Diarrhea caused by rotaviruses is a serious problem in calves and pigs, usually striking at less than three weeks of age and also after weaning. Mortality is usually low (10 to 20 percent) but morbidity is often 100 percent — once an animal is infected, it's more prone to other illnesses.

Saif and her students have been evaluating non-infectious rotavirus-like particles in calves and gnotobiotic (germ-free) pigs. FAHRP's germ-free animal facility is one of only a few worldwide. Funded by the National Institutes of Health and the U.S. Department of Agriculture, the project's ultimate goal is to create effective, safe and easy-to-use vaccines (oral and intranasal) to prevent rotavirus diarrhea in both animals and humans.

"We've been working with two methods of administering these virus-like particles," Saif explained. "One is to immunize the cows and provide passive immunity to the calves through antibodies in the milk. The second one is to immunize gnotobiotic pigs and study their immune responses against challenge with human rotavirus strains as a way of developing vaccines for humans."

Saif is also studying the relationship between porcine and bovine caliciviruses and their human counterparts. Because human enteric caliciviruses do not grow in cell culture, Saif is using the animal viruses as models for the human strains. Her objective is to adapt the human caliciviruses to cell culture and develop vaccines for both human and animal caliciviruses.

Saif's current research leading to the production of vaccines would have never been possible without her career-long efforts to identify new intestinal viruses and develop diagnostic tests and research methods for working with them in the laboratory. Saif and her students discovered, characterized and propagated in cell culture the first non-group A rotavirus described, a porcine group C rotavirus. She also identified the first porcine enteric calicivirus and successfully adapted it to cell culture — at present the only cultivable enteric calicivirus.

As technology develops, Saif also looks at the "good side" of enteric viruses.

"These viruses can be used to benefit mankind," she said. "This technology may someday lead to the use of bioengineered viruses to replace gene defects or to target the destruction of tumor cells."

In 2002, Saif became the first Ohio State researcher not based on the Columbus campus to be recognized as a Distinguished University Professor, the highest honor the university bestows upon faculty for their accomplishments in research, scholarly or creative work, teaching and service.

An internationally recognized scientist, Linda Saif has dedicated her extensive career to the discovery and characterization of enteric viruses. From her lab at OARDC's Food Animal Health Research Program, she leads the effort to develop vaccines against these deadly agents.

Gastroenteritis is a devastating plague in developing countries. A rotavirus vaccine would give many children a chance at life. WHO photo/P. Virot.

Virus-like particles such as these are the key to creating vaccines for rotaviruses and caliciviruses.

A 2002 Distinguished University Professor, Saif inspires her students to work hard and push the limits.