LAUSR

Objectives There is an urgent need to ameliorate the possibilities to transport the reconstituted mRNA vaccines from the centralized preparation centers to the vaccination sites to improve the COVID-19 vaccination campaigns. We have analyzed Pfizer-BioNTech and Moderna vaccine integrity under different movement conditions to provide information that may improve the distribution of vaccines to the target population. Methods Syringes of reconstituted Pfizer-BioNTech or Moderna COVID-19 vaccines were prepared in a laminar flow chamber to be subjected to a stability analysis in order to evaluate the impact of movement conditions on mRNA integrity. RNA integrity was checked by the lack of RNA peaks under the original mRNA peak in the electropherogram resulting from potential fragments from RNA degradation. Samples were then exposed for 180 min at room temperature (21±1C°, 55±10% of humidity) under different movement conditions. Results We report that the integrity of the mRNA of the COVID-19 reconstituted vaccines after continuous moderate movement at room temperature is maintained for at least three hours with values of fluorescence units (FU) under the original mRNA peak of 0.38±0.06 in Pfizer-BioNTech and 0.96±1.18 FU in Moderna, equal to the values obtained without movement (0.36±0.08 FU in Pfizer-BioNTech and 1.12±0.19 FU in Moderna). In contrast, the integrity of these vaccines exposed to repeated Vortex shaking was significantly impaired (p<0.001) with values under the original mRNA peak of 1.34±0.31 FU for the Pfizer-BioNTech and 5.03±1.16 FU for the Moderna samples. Conclusions The stability of these reconstituted vaccines here reported may improve the efficiency in the ground transportation and distribution of the vaccines, which may lead to shorter and more homogeneous vaccination in cities and rural areas.