A novel vaccine has protected cattle from respiratory syncytial virus (RSV) infection, according to new research.
The work – published in npj Vaccines – was conducted by a team at the National Institute of Allergy and Infectious Diseases in the US, the Institute for Research in Biomedicine in Switzerland and The Pirbright Institute in Surrey.
According to the authors, the strain of RSV that naturally infects cattle is closely related to human RSV, so the results suggest a similar RSV vaccine construct could provide protection in humans.
Containing a single, structurally engineered RSV protein, the experimental vaccine elicits high levels of neutralising antibodies in mice.
The protein is a stabilised version of the RSV fusion (F) glycoprotein in its initial conformation (pre-F), and while other vaccines have used the same protein in its final conformation (post-F), investigators found the immune response was much lower.
In this study, investigators immunised five three to six-week-old calves with the pre-F protein via two injections four weeks apart. They vaccinated another five calves with a post-F protein, while a third group of five calves received two placebo injections of saline.
Four weeks after the second immunisation, investigators infected all three groups with RSV.
It was found the calves vaccinated with the pre-F protein had high levels of neutralising antibodies, and that four of five were protected from RSV viral replication in the upper and lower respiratory tracts. In contrast, RSV was detected in all calves immunised with either the post-F protein or placebo.
Together the results support further evaluation of pre-F vaccines against RSV in both cattle and in humans, said the authors.
RSV causes the majority of respiratory disease in cattle, resulting in significant economic costs to the industry. In humans, RSV can cause serious bronchiolitis and pneumonia in young children and the elderly as well as in children and adults with compromised immune systems.
RSV infections are estimated to cause more than 250,000 human deaths annually.
- To read the study in full, visit the npj Vaccines website.