Here’s how the Johnson & Johnson vaccine is different

Here’s how the Johnson & Johnson vaccine is different   As the third authorized vaccine in the US, it’s important to point out what makes the Johnson & Johnson vaccine different from the ones created by Moderna and Pfizer/BioNTech.   One difference is how quickly the Johnson & Johnson vaccine offers protection. The protection against moderate to severe disease starts about two weeks after people get vaccinated. By four weeks after the shot, data from the clinical trial showed there were no hospitalizations or deaths.   Recent studies show a good level of protection with the first dose of the Moderna and Pfizer vaccines, but people don't get full protection until about two weeks after the second dose — so five to six weeks after the first dose.   Then there’s the fundamental difference that the Johnson & Johnson vaccine isn’t an mRNA vaccine like the other two.   The Johnson & Johnson vaccine uses viral vector technology. A common cold virus called adenovirus 26 is genetically engineered so that it can infect cells, but it won't replicate there. It cannot spread in the body, and won't give people a cold. Like the Pfizer and Moderna vaccines, it delivers genetic instructions.   Instead of being carried in little lipid balls, the genetic instructions are injected by the weakened virus into arm cells, and they make the pieces that look like part of the coronavirus spike protein — the knob-shaped structure that the virus uses to connect to cells.