First-in-human trial of mRNA vaccine

Moderna therapeutics has blazed a trail to the clinic with a first-in-human trial of an mRNA vaccine for avian influenza subtype H10N8. With the Phase 1 trial ongoing, they reported promising early results along with studies in multiple species in the journal Molecular Therapy. Moderna formulated two mRNAs encoding the hemagglutinin (HA) protein from either the H10N8 or H7N9 avian influenza subtypes in LNPs using NanoAssemblr technology. Both formulations generated high levels of neutralizing antibodies in multiple species. Early clinical results of the H10 mRNA vaccine indicate 87% of those vaccinated had hemagglutination inhibition titers of 40 or greater, a measure that indicates a 50% reduction in risk of contracting influenza. Importantly, reports of adverse events were similar to existing H1N1 vaccines in terms of their nature, severity, and frequency. These are promising results for mRNA vaccines which can be developed much faster than conventional vaccines in response to pandemic threats.

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First Demonstration of Zika Vaccine that Protects Against Congenital Defects

The Zika virus is a considerable threat given that the virus can be transmitted by mosquitoes and infections during or soon before pregnancy, is linked to birth defects including microcephally. In this follow up paper to their original mRNA-based Zika vaccine, Moderna Therapeutics report for the first time, a vaccine that successfully prevented zika-linked congenital disease in mice. Their formulation consisted of a non-amplifying mRNA encoding several Zika virus epitopes encapsulated into an LNP using NanoAssemblr technology. Following inoculation, infection and breeding, mice treated with this formulation exhibited more than 13,000-fold reduction in viral mRNA in the maternal and fetal brain tissues versus placebo. The synthetic nature of mRNA vaccines is important in this context as treating pregnant or immune-deficient people with live vaccines can be risky.

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