Experimental vaccine gives lasting protection in mice against CCHF ^{CEFR B2}

Crimean–Congo hemorrhagic fever (CCHF) is a high‑risk viral disease transmitted by ticks and livestock that can cause rapid fever, organ failure and internal bleeding, and it has no approved vaccines or treatments. A new preclinical study in npj Vaccines reports encouraging results for an experimental vaccine tested in mice. The work comes from a team that includes Scott Pegan at the University of California, Riverside and collaborators at several public agencies.

The vaccine platform is a virus-like replicon particle: it enters cells like the real virus but lacks the genetic material needed to replicate, so it cannot cause infection. Unlike most vaccines that target surface proteins, this candidate focuses on internal proteins, particularly the N protein that is normally hidden inside the virus. The authors suggest the N protein focus may underlie the unusually rapid antibody response and the platform's success.

Earlier work showed protection within three days of a single dose. In the new study researchers measured antibodies after one or two doses and found them detectable for up to 18 months in mice, an interval the team says roughly corresponds to several years in humans. Antibody levels in one- and two-dose groups were similar for about nine months, while animals receiving a booster developed stronger, more stable antibodies and showed better, longer-lasting protection.

Next steps include scaling production under Good Manufacturing Practice (GMP) ahead of human clinical trials. Partners at the Centers for Disease Control and Prevention are already exploring the same platform for other pathogens such as Nipah virus. The study lists collaborators at the CDC, the US Department of Agriculture and Auburn University, and notes partial support from the CDC and the National Institute of Allergy and Infectious Diseases of the NIH; the findings do not necessarily represent the official CDC position.