Congress’ top doctor urged lawmakers on Monday to move to a “maximal telework posture,” citing surging numbers of COVID-19 cases at the Capitol that he said are mostly breakthrough infections of people already vaccinated.

The seven-day average rate of infection at the Capitol’s testing center has risen from less than 1 percent to more than 13 percent, Brian P. Monahan, the attending physician, wrote in a letter to congressional leaders obtained by The Associated Press.

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Monahan said there has been “an unprecedented number of cases in the Capitol community affecting hundreds of individuals.” In what he said was limited sampling as of Dec. 15, about 61 percent of the cases were the new, highly contagious omicron variant while 38 percent were the delta variant.

Providing no figure, he said “most” of the cases are breakthroughs.

While such cases have not led to any deaths or hospitalizations among vaccinated lawmakers or congressional staff, Monahan said even mild infections can lead to six to 12 months of “long COVID.” A “reasonable estimate” is that 6 percent to 10 percent of cases could end up that way, he added.

Monahan urged congressional offices to “reduce in-person meetings and in-office activities to the maximum extent possible.”

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