Ohio State University scientists say they could be well on their way to developing a safe vaccine against norovirus — the pathogen that causes millions of gastrointestinal illnesses every year in the United States.

In a EurekAlert news release Tuesday, the researchers say their experimental vaccine against the human norovirus can generate a strong immune response in mice without appearing to cause the animals any harm.

They say the same viral vector-based technique they are using has shown promise in other agents designed to fight such infections as HIV and hepatitis C; the researchers are the first to test this vaccine design method’s effectiveness against norovirus. 

“The mice in our study developed a much higher antibody response to our vaccine candidate than they did to a more traditional vaccine. That’s one of the keys, to have a sustained antibody response, so that when the disease comes along, you can neutralize the virus and protect yourself,” said Jianrong Li, assistant professor of food science and technology at Ohio State and senior author of the study.

Developing a vaccine against norovirus is challenging, the news release explains, because it can’t be grown in cell cultures.The vector for this experimental vaccine is vesicular stomatitis virus (VSV), into which researchers insert the gene for the capsid, or outer shell, of the human norovirus. The recombinant vector virus serves as both the vaccine delivery vehicle and the agent that produces virus-like particles (VLP) that mimic human norovirus.

Li co-authored the study with Yuanmei Ma, a graduate student in food science and technology. The research appears in the March issue of the Journal of Virology.

The Centers for Disease Control and Prevention (CDC) estimates that norovirus causes 21 million gastric illnesses each year in the United States, but so far there is no specific vaccine or treatment.

Early clinical trials are underway for another norovirus vaccine, made by Ligocyte of British Columbia.