COVID-19 vaccines: What does 95% efficacy really mean? – LiveScience Photo: Scott Olson/Getty Images It doesn’t mean 5% of vaccinated people get infected. And it’s not just an academic question. How people understand these numbers affects how they think about the vaccine, whether they get it and how they behave after getting it, all of which have implications for the pandemic on a larger scale. Share this:TwitterFacebookLike this:Like Loading...