Unlike the newly approved vaccine, Pfizer/BioNTech and Moderna’s versions need to be administered in two shots, and require specialised freezers for storage and transportation. The ease of logistics has made US public health officials hopeful that the new vaccine can be administered quickly to elderly residents in door-to-door roll-out schemes.
The Johnson & Johnson vaccine also uses a different technology than the Pfizer/BioNTech and Moderna ones: instead of using mRNA to deliver the genetic material for a bit of the coronavirus into the body, it couches a part of the coronavirus gene in another harmless virus called adenovirus. Both techniques result in the recipient’s immune system learning to recognise and fight Covid-19.
Johnson & Johnson says it currently has approximately 4m doses ready to ship in the US, that it will be able to provide 20m doses to the US by the end of March, and 100m by the end of June.