Thread by @SCOTTeHENSLEY

We developed a new multivalent mRNA vaccine against all known influenza virus subtypes. Our study describing the vaccine was just published in @ScienceMagazine. 1/n
science.org/doi/10.1126/sc…

We created an mRNA vaccine expressing HAs from all 20 flu types. First, we vaccinated mice and found that this multivalent vaccine elicits robust antibody responses reactive to every HA. 2/n

Our new vaccine does not simply elicit antibodies that cross-react to every known influenza subtype. Instead, we found that that the vaccine elicits distinct antibody lineages against all 20 different flu HAs. 3/n

The vaccine elicits both neutralizing and non-neutralizing antibodies against diverse influenza subtypes with pandemic potential. 4/n

The vaccine protected mice against viruses that were similar to the vaccine components. But more importantly, the vaccine prevented severe disease and death against viruses that were distinct from the vaccine components. This resembles a pandemic situation. 5/n

And that is our goal: to elicit a baseline level of immunity in the population that would not necessarily prevent infections with new pandemic strains--but rather prevent severe disease and death caused by new pandemic strains. 6/n

Here is an important part: we found that our vaccine elicits strong antibody responses in animals with and without prior flu exposures. We think that this vaccine has the potential to elicit responses in children, as well as the rest of us who have already encountered flu. 7/n

We found very similar results in ferrets. The vaccine elicited antibodies against all 20 HA components and protected animals from an antigenically distinct viral strain. Thanks to @Lakdawala_Lab and @SageVle
for completing ferret experiments. 8/n

We are now testing the vaccine in non-human primates and planning phase 1 human studies. We think this vaccine has the potential to elicit immunity that could be quickly recalled to significantly reduce severe disease and death from our next flu pandemic. 9/n

We've been working on this multivalent mRNA flu vaccine for years--most of this work was completed before the COVID pandemic. I'm grateful to work with the brilliant @WeissmanLab, and I'm so happy to see how mRNA vaccines proved to be so useful during the COVID pandemic. 10/n

Last but not least, I want to acknowledge my lab--especially @pennbgs @IGGPenn graduate student, Claudia Arevalo, who completed most of the experiments for this study. I also acknowledge @NIH, @CEIRRNetwork, and @PennMedicine for their support. 11/n

Thank you @akelvinlab for writing such a nice perspective of our study. 12/n
science.org/doi/10.1126/sc…