Breakthrough COVID-19 cases expected to become increasingly common Experts blame the rise of the delta variant and declining efficacy of coronavirus vaccines but say there is no need for alarm. Roll Call

A breakthrough case of COVID-19 occurs when a person contracts COVID-19 at least two full weeks after the final dose of the vaccine. The Centers for Disease Control and Prevention tracks only breakthrough cases that result in hospitalization or death, as these incidences are both serious and very rare.

... Echoes of the pandemic’s early months are resounding through the halls of hospitals, with an average of more than 90,000 patients in the United States being treated daily for Covid. Once again, many hospitals have been slammed in the last two months, this time by the Delta variant, and have been reporting that intensive care units are overflowing, that patients have to be turned away and even that some patients have died while awaiting a spot in an acute or I.C.U. ward.