Preparation of H1N1 microneedles by a low-temperature process without a stabilizer.

(1) Plaque reduction neutralization test (PRNT) for virus neutralization. IM (H1N1): intramuscular administration, RT-MN-T: room-temperature H1N1 microneedles with stabilizer, LT-MN-T: low-temperature H1N1 microneedles with stabilizer, LT-MN: low-temperature H1N1 microneedles without stabilizer. (2) The IM administration group had a lower neutralizing antibody than the microneedle group. (3) The microneedle group prepared at low temperature showed a similar antibody titer regardless of the addition of a stabilizer. (4) When the whole microneedle production process is performed at a low temperature, the influence of the stabilizer and the denaturation of the antigen can both be minimized, and as a result, immunogenicity can be induced effectively.