J&J has mRNA.
Unlike the Pfizer-BioNTech and Moderna vaccines, the Johnson & Johnson vaccine does not use messenger RNA (mRNA) to help the body build its defenses against the virus. Instead, it is an andenovector vaccine. The scientists behind the Johnson & Johnson vaccine added the gene for the coronavirus’ signature spike protein to an adenovirus, a common virus that causes colds or flu-like symptoms. However, the adenovirus was modified so it can enter cells but can’t replicate or cause illness.