Brooke Fiala and Neil King

A first-of-its-kind nanoparticle vaccine candidate for respiratory syncytial virus has been designed in an international research effort. RSV is second only to malaria as a cause of infant mortality worldwide. The new vaccine elicits potent neutralizing antibodies against RSV in both mice and monkeys. The animal research findings, reported March 7 in the journal Cell, pave the way for human clinical trials.

RSV infects nearly all children by the age of three. Infection typically causes mild symptoms, but can be more serious in newborns, immunocompromised individuals and the elderly. In the United States, RSV is the leading cause of pneumonia in babies under a year old.

According to the National Institute for Allergy and Infectious Disease, RSV is responsible for an estimated 64 million infections and causes 160,000 deaths globally each year. About 99 percent of the RSV deaths occur in developing countries. After considerable research, several vaccine candidates are in preclinical or clinical testing. As yet no RSV vaccine is ready for use in disease prevention.

“It has historically been challenging to produce an RSV vaccine that is both safe and effective, but exciting new vaccine design strategies continue to emerge,” said Brooke Fiala, a research scientist at the University of Washington School of Medicine’s Institute for Protein Design and a lead author of the study. “We hope to move this vaccine candidate into clinical trials soon and to continue producing vaccines for other diseases as well.”

Just as a leather soccer ball is stitched from geometric patterns, the new vaccine’s core is a computer-designed nanoparticle made of different parts shaped like pentagons and triangles. Each nanoparticle is more than ten million times smaller than a poppy seed. The outsides of these nanoparticles were fitted with inert RSV proteins to create the vaccine.