Claims about Iceland

We find that people diagnosed outside of quarantine are 89% more infectious than those diagnosed while in quarantine, and infectiousness decreases as a function of the time spent in quarantine. Furthermore, we find that people of working age, 16-66 years old, are 47% more infectious than those outside that age range. Lastly, the transmission tree enables us to model the effect that given population prevalence of vaccination would have had on the third wave had they been administered before that time using several different strategies. We find that vaccinating in order of ascending age or uniformly at random would have prevented more infections per vaccination than vaccinating in order of descending age [emphasis added].

That is from a new paper by lots of people with Icelandic names, via Eric Topol.  This is not yet confirmed or general, but it does resurrect the idea of vaccinating many younger people first, due to their (possibly) greater ability to spread the virus.  Note also the data here are taken from Iceland’s third wave, which might further limit the generality of the result.