Bunya RNA 1: Preclinical development
BunyaVax RNA particle technology was used to develop a vaccine against influenza virus. Influenza remains one of the most important zoonotic diseases, affecting both animal and human health. The virus has a demonstrated ability to cause global outbreaks (pandemics). These large outbreaks are caused by influenza viruses that have changed their appearance by antigenic variation. Apart from introducing mutations in the influenza virus genome, resulting in antigenic drift, the virus has the capability to exchange genome segments with related influenza viruses. This so-called antigenic shift generally occurs in natural target species, such as poultry and swine. Particularly swine have been implicated as “mixing vessels” of influenza viruses that have caused large outbreaks among humans. In addition to the risks for human health, swine influenza results in significant economic losses in the swine industry. Although vaccines again swine influenza virus (SIV) are available, these vaccines offer poor protection against circulating field strains. There is thus an important need for novel efficacious vaccines that can quickly be updated to match circulating field strains. The RNA particle technology of BunyaVax is particularly suitable for this application.
BunyaVax RNA particles are highly infectious and capable of genome replication and gene expression, but are unable to produce progeny virions. By virtue of these features, BunyaVax RNA particle-based vaccines optimally combine vaccine efficacy with safety.
In a pre-clinical study with mice, BunyaVax RNA particles expressing the influenza hemagglutinin of influenza A virus H1N1 were applied via either intramuscular or intranasal route. A single vaccination via either route protected 100% of mice from a lethal challenge dose. Interestingly, whereas intramuscular vaccination elicited superior systemic immune responses, intranasal vaccination provided optimal clinical protection.
BunyaVax is continuing pre-clinical trials with pigs and will develop vaccines for clinical evaluation.