Question: My daughter received the Johnson & Johnson one-dose vaccine on Friday!  How long does she have to wait to be considered fully vaccinated?

Answer:  Your daughter is considered fully vaccinated 2 weeks after vaccination, and available evidence indicates that she will be even more protected 4 weeks after vaccination.  CDC notes, “People are considered fully vaccinated: a) 2 weeks after their second dose in a 2-dose series, such as the Pfizer or Moderna vaccines, or b) 2 weeks after a single-dose vaccine, such as Johnson & Johnson’s Janssen vaccine.”  Data from J&J’s clinical trial show that vaccine efficacy to protect against severe disease continues to increase over time.  Specifically, clinical trial data show that J&J’s vaccine efficacy against severe/critical COVID-19 occurring at least 14 days and at least 28 days after vaccination is 76.7% (95% CI: 54.6, 89.1) and 85.4% (95% CI: 54.2, 96.9), respectively (Table).  Of course, no vaccine is 100% effective against infection and there’s still a lot we are still learning, so please ask your daughter to continue following public health guidelines to protect herself and others.  In that vein, CDC offers guidance on what fully vaccinated people can do and shouldn’t do (Figure).

Table. Johnson & Johnson Vaccine Efficacy over Time, by Disease Severity and Place/Variant (from FDA EUA Fact Sheet)

Figure. What you can do after being fully vaccinated (from CDC)