We don’t know who the support staff are, it could be people who don’t travel. Regardless, the J&J vaccine was 66.3% effective at preventing illness, it was approved because it had high efficacy at preventing hospitalization and death.
How Well the Vaccine Works
- The J&J/Janssen vaccine was 66.3% effective in clinical trials (efficacy) at preventing laboratory-confirmed COVID-19 illness in people who had no evidence of prior infection 2 weeks after receiving the vaccine. People had the most protection 2 weeks after getting vaccinated.
- The vaccine had high efficacy at preventing hospitalization and death in people who did get sick. No one who got COVID-19 at least 4 weeks after receiving the J&J/Janssen vaccine had to be hospitalized.
- Early evidence suggests that the J&J/Janssen vaccine might provide protection against asymptomatic infection, which is when a person is infected by the virus that causes COVID-19 but does not get sick.
- CDC will continue to provide updates as we learn more about how well the J&J/Janssen vaccine works in real-world conditions.