The analysis misses some aspects of how the phase 3 study is performed. Even if there were much more than 90% of the sick people in the placebo group, it doesn't follow at all that the vaccine is "more effective" than 90%.<p>The reason is, there were only 94 sick people observed. But to calculate efficacy, one has to factor in that the population on which the final vaccine is to be applied doesn't have to reflect by age, existing risk factors etc. the group of people who got sick up to now.<p>It's very probable that people who got sick in the study aren't exactly representative of the whole populations.