MRNA, or messenger RNA, is genetic material that incorporates instructions for making proteins. Inside the body, the mRNA enters human cells and instructs them to provide the “spike” protein discovered on the floor of SARS-CoV-2, the virus that causes COVID-19. The body recognizes the spike protein as an invader, and begins producing antibodies against it. Soon after, the cell breaks down the mRNA into harmless pieces If the antibodies later encounter the precise virus, they are ready to recognize and destroy it earlier than it causes sickness. This was lower than vaccine effectiveness against hospitalization for the Moderna mRNA vaccine (93%) or the Pfizer/BioNTech mRNA vaccine (88%).