▶ Watch Video: Fears over another wave of COVID-19 in U.S. rattle stock markets

The White House has not disclosed past breakthrough cases of COVID-19 among fully vaccinated staff members, although none of the cases have occurred among commissioned officers, White House press secretary Jen Psaki confirmed during Tuesday’s press briefing. 

Psaki’s comments came after a White House official confirmed Tuesday that a fully vaccinated White House official tested positive for the virus off campus, although the White House Medical Unit determined the individual had no close contacts among White House principals and staff. The breakthrough case comes as multiple members of a Texas delegation to Washington, D.C., tested positive, despite being fully vaccinated. After meeting with members of the Texas delegation, a fully vaccinated spokesperson for House Speaker Nancy Pelosi tested positive as well, according to Pelosi’s deputy chief of staff. 

Psaki confirmed to CBS News senior White House and political correspondent Ed O’Keefe that there have been other breakthrough cases in the White House that were not previously disclosed. She emphasized that the Biden team has committed to disclosing positive tests of commissioned officers, and told CBS News Radio White House correspondent Steven Portnoy that none of the breakthrough cases were among commissioned officers. 

Psaki declined to say how many breakthrough cases have occurred among unvaccinated individuals, and it is unclear whether the cases before Monday’s case have been symptomatic or asymptomatic. 

In confirming Monday’s breakthrough case, Psaki stressed that cases in vaccinated individuals are usually mild. 

“We know that there will be breakthrough cases, but as this instance shows, cases in vaccinated individuals are typically mild,” Psaki said from the briefing room podium. “The White House is prepared for breakthrough cases with regular testing. This is another reminder of the efficacy of the COVID-19 vaccines against severe illness or hospitalizations. And of course, we wish our colleague a speedy recovery.”

Psaki also insisted that the White House operates in accordance with the advice of public health experts, and the frequency of staff testing depends on proximity to the president. 

“We have a robust infrastructure to ensure compliance with these protocols, and we are asking staff to also monitor themselves for symptoms and staff off campus if they develop symptoms,” Psaki said. “So the news today is that while breakthrough cases will happen, the vaccines are effective, and prevent against serious illness and death. we’ve seen that statistically across the country, with 99.5% of cases in hospitals being for individuals who are not vaccinated. And we will continue to abide by CDC guidelines.”

The evidence available shows those who are vaccinated are significantly less likely to suffer serious outcomes from COVID-19 than those who are unvaccinated. Earlier this month, Dr. Anthony Fauci said on NBC’s “Meet the Press” that about 99.2% of recent deaths are among the unvaccinated. The Biden administration has taken up the phrase that this is becoming a “pandemic of the unvaccinated.” 

Former President Trump’s White House was consistently criticized for failing to disclose positive cases of COVID-19 before the vaccine was available, often leaving it up to reporters to disclose cases.  

— CBS News’ Ed O’Keefe, Steven Portnoy and Alex Tin contributed to this report.