Researchers at the National Institute of Allergy and Infectious Diseases (NIAID) have developed a new vaccine for inoculating cattle from respiratory syncytial virus (RSV).
Since RSV strains between cattle and humans are closely related, the development of this vaccine may lead to a breakthrough in combating RSV in both species, according to an NIAID news release.
Most of the respiratory diseases cattle contract are from RSV, resulting in significant costs to the cattle industry. When contracted by humans, it can cause bronchiolitis and pneumonia in young children, the elderly and those with a compromised immune system. The virus is responsible for more than 250,000 deaths a year worldwide, according to the release.
Currently, there is no licensed vaccine to prevent infection in humans, and although vaccines for cattle use are available, they have been scrutinized for their safety and effectiveness.
The recently developed vaccine contains a single, structurally engineered RSV protein, which elicited high levels of neutralizing antibodies in mice. The protein, called pre-F, is a stabilized version of the RSV fusion (F) glycoprotein in its initial conformation, unlike current vaccines that utilizes the same protein but in its final or post-F conformation.
In a study using three groups of five 3- to 6-week-old calves, NIAID researchers immunized two of the groups through two separate injections, four weeks apart from each other. One group received the new vaccine containing a pre-F protein, one was given a post-F and the last group was injected with saline as the control.
The researchers then exposed all three groups to RSV. Results showed RSV had in both the control and the calves vaccinated with the post-F protein. However, the group of calves vaccinated with the pre-F protein had more than 100 times of the number of antibodies than the post-F group, and four of the five calves were successfully inoculated.
In light of these results, the NIAID has begun its Phase 1 human trials using a similar build of the vaccine.
