High attack rate of COVID-19 in an organized tour group of vaccinated travelers to Iceland.

In a COVID-19 outbreak in a group of 25 twice-vaccinated Israeli travelers, the attack rate was 84%, despite negative pre-flight PCR tests. This extremely high breakthrough infection rate is attributed mainly to close and prolonged exposures during long bus-drives. Masking, distancing, and personal responsibility are required to avoid such outbreaks.