I am looking forward to reviewing the phase 3 trial results on the Janssen |Johnson & Johnson Vaccine which should be available soon for FDA review. It may be only a single injection and uses a different technology than the mRNA Pfizer |BioNTech and Moderna vaccines. This vaccine uses a human modified human adenovirus type 26 and covid-19 gene that encodes for the spike protein. The modification prevents the adenovirus from being replicated to cause disease, but also has component of the Sars-CoV-2 gene for the spike protein that will cause our immune cells to react and attack the Covid-19 virus. Using an adenovirus adjuvant is not new. I like this video by Janssen, explaining how the vaccine works.
The Astra Zeneca vaccine uses similar technology but uses a modified simian (monkey) adenovirus.