8. Will the vaccine 100% work?
“Safety and efficacy are the two most important goals for every vaccine. Safety is exactly what it sounds like: is the vaccine safe to give to people? Some minor side effects (like a mild fever or injection site pain) can be acceptable, but you don’t want to inoculate people with something that makes them sick.
Efficacy measures how well the vaccine protects you from getting sick. Although you’d ideally want a vaccine to have 100 percent efficacy, many don’t. For example, this year’s flu vaccine is around 45 percent effective.”
Read more: https://www.gatesnotes.com/Health/What-you-need-to-know-about-the-COVID-19-vaccine