The present invention is directed to (the use of) a solution containing at least one nucleic acid (sequence) and free mannose for lyophilization, transfection and/or injection, particularly of RNA and mRNA. The inventive solution exhibits a positive effect on stabilization of the nucleic acid (sequence) during lyophilization and storage but also leads to a considerable increase of the transfection efficiency of a nucleic acid. It thus also increases in vivo expression of a protein encoded by such a nucleic acid upon increased transfection rate. The present invention is furthermore directed to a method of lyophilization using the mannose-containing solution, to pharmaceutical compositions, vaccines, kits, first and second medical uses applying such a mannose-containing solution and/or a nucleic acid (sequence) lyophilized or resuspended with such a solution.
