A 45-year-old woman participates in a randomized influenza vaccine trial. She receives the inactivated influenza vaccine and remains asymptomatic throughout the season with normal vital signs (BP 118/76, HR 72, RR 14, Temp 37°C). Over one influenza season, 6 of 1,000 vaccinated participants develop symptomatic infection confirmed by RT-PCR, compared to 30 of 1,000 unvaccinated controls. No serious adverse events occur in the vaccine group. Which of the following represents the vaccine efficacy of this immunization?
- A)40%
- B)80%GABARITO
- C)20%
- D)60%
- E)94%
Explicação
Vaccine efficacy is calculated as (risk in unvaccinated minus risk in vaccinated) divided by risk in unvaccinated. The unvaccinated risk is 30/1000 = 3%, and the vaccinated risk is 6/1000 = 0.6%; therefore efficacy = (3.0% - 0.6%)/3.0% = 80%. This reflects the... Ver explicação completa e trilha adaptativa →