Is it safe? After a year worrying about that question rather intensely, we’re getting closer and closer, and closer to an affirmative answer. But our rapid mobilization on vaccines — and simultaneous reopening of schools, restaurants and workplaces — is a complex dance, raising a blizzard of fresh questions as we zero in on answering that primary one. And now is the time to really pay attention. Science shows we’re all likely to push harder and take more risks the closer we are to the finish line. More than 2 million Coloradans have been fully vaccinated now, which is 43.8 percent of the eligible population. We’re hearing from state health officials that the ultimate goal is 70 percent vaccinated, which would give us “herd immunity,” the threshold when most of the population is immune to Covid-19, providing indirect protection to those who are not immune.