Virus model may offer new approach for childhood diarrhea vaccine

Scientists have created a model of rotavirus, the most common cause of severe diarrhea and vomiting in children.

Rotavirus infects almost all children, usually between six months and two years of age. The virus kills an estimated 600,000 children annually worldwide, according to the U.S. Centers for Disease Control.

Senior investigator Stephen Harrison of Children's Hospital Boston and his colleagues in Boston and Houston built a model of the key proteins in the virus.

Knowing the structure of the proteins may help scientists to produce safer, cheaper vaccines against rotavirus, the researchers said.

In the U.S., the only vaccine licensed for rotavirus, called RotaShield, was pulled from the market in 1999 because of fears of complications, according to the World Health Organization.

RotaShield was made from live viruses.

In Thursday's issue of the journal Nature, the American researchers said the proteins contain many of the key parts needed to mount an immune response against the virus.

The findings may offer a way to make a vaccine without having to use the whole virus.

To investigate, scientists compared the three-dimensional structure of proteins, atom by atom, to electron microscopy images of the virus.

The team was able to determine how the virus seems to break through membranes to infect cells.

The researchers suggest the findings may shed light on how similar viruses including those that cause the common cold are able to enter cells.