> 60% didn't get it at all and 40% got it with significantly less negative effects

We don't know that. As with the Pfizer and Moderna trials, the endpoint was incidence of disease, and only people with disease symptoms were tested. 60% fewer people experienced symptoms in the treatment group than the control group, but some of those may well still have "gotten it." There were very likely asymptomatic infected people in both groups, and we have no idea how many there were, or how the numbers different between groups. For all we know, just as many people in the treatment group were infected as in the control group, they were capable of spreading infection the whole time, and all the vaccine did was suppress their symptoms. (Again: possibly true of any of the vaccine candidates.)