For most children and adults, catching respiratory syncytial virus (RSV) is just like catching a cold--a few days of a stuffed up nose, sore throat or cough and then it's gone. But for babies, especially premature babies, and other vulnerable children, it can lead to pneumonia, bronchiolitis and long-term wheezing. A team at the University of Saskatchewan, along with the company VIDO-InterVac, is developing a nasal vaccine that shows promise in the lab, and could be just two years away from clinical trials.
The vaccine targets a protein on the surface of the virus, which is easily accessible. This protein allows the virus to gain entry into the cell. It also includes two adjuvants to pep up the immune response, and is packaged in a particle that resists the body's efforts to sweep out foreign substances. The vaccine was effective in studies in mice and cotton rats.
One of the issues with vaccinating young babies is that they still have maternal antibodies in their bloodstreams, from before birth and through breast milk. While these antibodies are very valuable to protect the child from infection, they can also inactivate vaccines. The advantage of the nasal route, which uses a platform technology developed at VIDO-InterVac, is not only that its less distressing for the baby, but also that it triggers an immune response in the nose and lungs, bypassing the bloodstream and the maternal antibodies.
"The challenge is to vaccinate while (maternal) antibodies are circulating, because these antibodies can inactivate the virus and prevent infection, but also inactivate the vaccine," says Sylvia van den Hurk of the University of Saskatchewan and VIDO-InterVac, which is based on the university campus. "You have to formulate your vaccine to avoid that."
The vaccine development has been funded by the Krembil Foundation and Bill and Melinda Gates Foundation and the Saskatchewan team has recently received a grant from the Canadian Institutes of Health Research (CIHR). The researchers are working with Pan-Provincial Vaccine Enterprise to push the vaccine through Phase I trials, and investigations are ongoing to find out more about how the vaccine actually works.
- read the press release