3HA Nanoparticle Stability Data

Vaccine distribution infrastructure remains
inadequate in many parts of the world, and it is estimated that up to 40-50% of
all vaccine doses are wasted in certain countries. Vaccines that can maintain
viability outside of the cold chain would decrease vaccine wastage and increase
immunization rates in regions of the world with underdeveloped vaccine
distribution infrastructure. We examined the potential of crosslinked protein
nanoparticles, made from trimerized influenza hemagglutinin (3HA), to maintain
immunogenicity after cold-chain-independent storage. We found that the
nanoparticles could be stored for 112 days at room temperature without any loss
in hemagglutinating activity or immunogenicity, and that nanoparticles could be
stored at 37°C for 2 weeks without any loss in hemagglutinating activity. As
vaccine development moves towards the use of recombinant subunit antigens, our
results demonstrate the potential of crosslinked antigen nanoparticles as an
immunogenic vehicle for bringing effective vaccines to underdeveloped regions
outside of the cold chain.