The Elderly vs. Essential Workers: Who Should Get the Coronavirus Vaccine First?

Neither. Those in the the 18-29 age group are the most likely to contract Covid-19 and thus most likely to spread it. They express fewer symptoms (making them more likely to ignore it and go out/party) and have far more social contact. Therefore, they are generally the super-spreaders and should be vaccinated first and most aggressively.

This age group also has fairly heavy overlap with essential workers demographically. Vaccinate them, and you stop many spreading events. Then concentrate on the most vulnerable.