In sum, Dr. Masuda deemed the safety profile “clinically acceptable.”
Session chair Karina Butler, MD, of Temple Street Children’s University Hospital, Dublin, raised the question of how might this vaccine, which may require two doses in younger children, fit into an already crowded pediatric immunization schedule – will parents and physicians embrace it?
Dr. Masuda replied that noroviruses are the No. 1 cause of acute gastroenteritis worldwide and there is a clamor for development of effective vaccines to protect the groups that bear the greatest burden of disease, including children, the elderly, military personnel, cruise ship vacationers, and others who experience crowded conditions. He expressed confidence that a safe and effective vaccine will be in high demand.
“In the future, we’ll look at the possibility of a combination vaccine,” he added.
In response to audience questions, Dr. Masuda said that in adult studies higher levels of immunogenicity have been achieved after vaccination, compared with natural infection; however, there are as yet no pediatric data on that score. Also, investigators have seen evidence of cross-reactivity to the vaccine in some but not all naturally circulating nonvaccine strains.
The vaccine formulation being carried forward into advanced clinical trials in adults is 15 mcg of GI.1/50 mcg of GII.4c ().
The phase 2 study presented by Dr. Masuda was supported by the U.S. Army.