Experimental 'dual vaccine' takes aim at norovirus, the top foodborne illness

The vaccine development process

The experimental vaccine against both rotavirus and norovirus was created by the researchers by incorporating a protein gene from the outer surface of human norovirus into the genome of a laboratory rotavirus strain.

The modified rotavirus was then given orally to immunocompromised infant mice, and blood and fecal samples were taken four, six, and eight weeks after the initial immunization. After nine weeks, the mice were given a booster by injection, and samples were taken a week later.

Future of the vaccine

The experimental vaccine elicited a strong immune response in mice, with neutralizing antibodies against both rotavirus and norovirus detected in the blood of nine out of 11 mice tested and in the intestines of all 11 mice. These antibodies were also able to neutralize both viruses in human "mini-gut" cultures in vitro. The next phase of the research will be to investigate whether immunized animals are less likely to contract norovirus or die from it.

The study's strength lies in its innovative approach, which has the potential to speed up the development of vaccines for various intestinal pathogens causing diarrhea, particularly in countries with limited resources where these infections are prevalent.

As there are several intestinal pathogens lacking effective vaccines or treatments, the researchers propose that any gene from an organism infecting the intestinal tract could be incorporated into the rotavirus vaccine to create a bivalent vaccine.

The scientists are optimistic that this approach could lead to progress against norovirus, a virus that has been difficult to control so far.

Study abstract

Despite being a prevalent viral infection that causes numerous cases of food poisoning and kills thousands of children each year, there is currently no effective way to control norovirus. However, a new study conducted at Washington University School of Medicine proposes a unique method for creating a norovirus vaccine using the highly successful rotavirus vaccines that are already distributed worldwide. By adding a key norovirus protein to a harmless rotavirus strain, the researchers were able to develop an experimental rotavirus-norovirus combination vaccine. 

In animal testing, the vaccine successfully produced neutralizing antibodies against both viruses. This approach offers hope for finally making progress in the fight against norovirus by utilizing the existing distribution networks for rotavirus vaccines. Additionally, this technique has the potential to expedite vaccine development for other diarrheal infections that pose significant challenges, particularly in resource-limited areas where such infections are prevalent.