evidence: Getting COVID-19 carries a greater risk of developing health complications compared to COVID-19 vaccination. COVID-19 mRNA vaccines contain messenger RNA (mRNA) that provides the blueprint for making spike protein. Modified mRNA isn’t intrinsically artificial. Modifications to mRNA also occur naturally in humans and are used to regulate gene expression. Scientists took their cue from nature when modifying COVID-19 vaccine mRNA to improve its stability and efficiency in protein synthesis.