Reconstituted mRNA COVID-19 vaccines may maintain stability after continuous movement.

Objectives: There is an urgent need to ameliorate the possibilities of transporting reconstituted mRNA vaccines from the centralized preparation centres to the vaccination sites to improve the efficiency of the vaccination campaign against coronavirus disease 2019 (COVID-19). We have analysed the integrity of the Pfizer-BioNTech and Moderna vaccines 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 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 ± 1°C, 55 ± 10% humidity) under different movement conditions.

Results: We report that the integrity of the mRNA in the reconstituted COVID-19 vaccines after continuous moderate movement at room temperature is maintained for at least 3 hours, with values of fluorescence units (FU) under the original mRNA peak of 0.38 ± 0.06 in the Pfizer-BioNTech vaccine and 0.96 ± 1.18 FU in the Moderna vaccine, equal to the values obtained without movement (0.36 ± 0.08 FU in the Pfizer-BioNTech and 1.12 ± 0.19 FU in the 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 reported here may improve the efficiency of the ground transportation and distribution of the vaccines, which may lead to shorter and more homogeneous vaccinations in cities and rural areas.