They are the latest examples of 'breakthrough infections,' and doctors say that they are neither common nor surprising. Notably, one of the breakthrough cases is an Oahu health care worker who had traveled to not one, but several US cities after getting vaccinated. It is not clear whether any of the three breakthrough infections were caused by variants or whether the patients' samples are being tested for variants. So far, breakthrough infections have been quite rare. The CDC says it is investigating all reports of breakthrough cases but does not yet publicly share national rates.

Source: Daily Mail March 22, 2021 17:05 UTC