(NBC News) - The Biden administration is issuing new guidance Tuesday recommending indoor masking in areas with high transmission rates after reviewing new data suggesting fully vaccinated individuals are not just contracting Covid-19, but could be carrying higher levels of virus than previously understood and potentially able to infect others, according to multiple sources close to the discussion.
Administration officials still contend that fully vaccinated individuals represent a very small percentage of transmission, which is primarily occurring among unvaccinated people.
The new guidance comes after an internal debate among health officials: Whether to respond to these findings by simply informing the public about them or by recommending additional restrictions, including a return to uniform indoor masking for both vaccinated and unvaccinated individuals.
Administration officials had been struggling in recent days with how to respond to the rising number of Covid-19 infections and hospitalization among those who are fully vaccinated amid pressure from public health experts to put mask recommendations back in place. Much of Biden's domestic agenda rides of moving the country past the pandemic and shifting the focus to other priorities, like infrastructure and voting rights.
Within the administration there had been concern that a focus on masking could take away a key incentive for people to get vaccinated, which they believe was a factor for many people in choosing to get the shot. Some argued the best way to keep the virus under control was to double down on efforts to get as many vaccinated as possible.
“I understand how challenging this is in terms of the vaccine hesitancy and wanting people to get the vaccine,” said Leana Wen, a former Baltimore health commissioner and a professor and physician at Georgetown University. “But the Biden administration made a serious error in the first place with their CDC guidance on masks and it is really hard to put the genie back in the bottle.”
While the Covid-19 vaccines have led to a steep decline in new infections, deaths and hospitalizations, multiple studies have found they are less effective against the new delta variant that now accounts for the vast majority of infections in the United States.
With the virus still widely circulating in many places where there are low vaccination rates, that has put the vaccinated at increased risk the virus will break through its layer of protection. In some states, particularly in the South, just over a third of the population is fully vaccinated.
Given how infectious the variant is some health experts are now also questioning the effectiveness of standard cloth masks and advocating for more effective masks like the KN95 to be recommended for indoor use for all, particularly among the elderly and immunocompromised. One study found those infected with the delta variant carried 1,000 times the virus as with earlier strains.
But administration officials had been concerned a return to widespread masking mandates could actually stunt the broader vaccination drive by taking away an incentive for getting the shots.
Despite a push over the last two month by the Biden administration to increase the number of people getting vaccinated, the number of daily shots has plateaued at around 500,00 per day and Biden has yet to reach his July 4 goal of getting 70 percent of adults at least patricianly vaccinated.
The worrisome data comes just weeks after the Centers for Disease Control said vaccinated individuals can go about their business without masks.
But the emergence of the new variant had led Wen and other physicians, including those who advised Biden during the transition, to begin recommending that people who are vaccinated wear masks indoors, especially if they are elderly, have a weakened immune system or are in an area with a high rate of infections, until vaccination rates can get up.
“I think they should say we made a mistake with our guidance earlier because we were reliant on the honor system and the honor system didn’t work,” Wen said earlier this week. “As a result, too many people are unvaccinated and the delta variant spreads and we have a different situation in our country now.”
Just how widespread infections among the vaccinated are in the U.S. is unknown. The CDC said in May it would stop monitoring the number of infections in vaccinated people aside from cases where a fully vaccinated person was hospitalized or died.
The CDC also recommended that people who are fully vaccinated not get tested after exposure to someone who has Covid-19 if they aren’t experiencing symptoms and refrain from routine testing.
That has left doctors saying they feel they are flying blind in trying to assess the risk the new variant poses to their patients and relying on data out of other countries like Israel, where researchers released data last week showing the Pfizer vaccine was just 39 percent effective against preventing infection from the delta variant and 91 percent effective at preventing severe disease.
“It is a very short-sighted policy to not be collecting that data because they are worried that it will be misinterpreted by people who think vaccines don’t work,” said Christopher Murray, director of the Institute for Health Metrics and Evaluation at the University of Washington. “It is essentially making us a little blind to what is actually going on.”
But despite the lack of data from the CDC, anecdotal evidence is widespread, with high-profile cases of groups of fully-vaccinated individuals getting infected — like a group of democrats from the Texas State Legislature, a White House official, a group of New York Yankees, and an Olympic athlete.
Michael Osterholm, director of the Center for Infectious Disease Research at the University of Minnesota who advised the Biden transition, said he is particularly concerned about the increasing number of instances he is hearing about where groups of vaccinated individuals are becoming infected. The CDC has said the data indicates the vaccinated can’t spread the virus to other vaccinated people, but Osterholm said the clusters of cases among the vaccinated suggest otherwise.
In one cluster of more than 200 cases in Provincetown, Mass. 70 percent of the Covid-19 positive cases since July 1 have been among vaccinated individuals, town manager Alex Morse said in an MSNBC interview.
A small percentage of those who are fully vaccinated also continue to be hospitalized and die from the virus, particularly in areas seeing a surge in cases from the delta variant.
At Texas Medical Center in Houston, 10 percent of more than 250 hospitalized Covid patients were vaccinated, a hospital spokesperson said. In Las Vegas, 11 percent of Covid hospitalizations in July had been fully vaccinated, according to the Southern Nevada Health District. A spokesperson for University of Kansas Health Systemsaid on July 15 that 16 percent of inpatients had been fully vaccinated.
Hospital officials added, though, that those who are vaccinated are less likely to be in the ICU or die, and nearly all who were admitted after vaccinations had serious underlying conditions.
Nationwide, the Center for Disease Control and Prevention hastracked more than 4,000 cases of fully vaccinated people being hospitalized with symptoms of Covid as of July 19, up 9 percent from the week earlier. The agency said a total of 849 vaccinated people have died, including 58 the week of July 12, according to data reported to the CDC by local health departments.
But administration officials, including Psaki and White House Covid coordinator Jeffrey Zients, have repeatedly said 97 percent of people who are hospitalized with Covid-19 are unvaccinated, citing a figure based on data from January to April when the U.S. was coming off of the winter surge, fewer people were fully vaccinated and the country wasn’t grappling with the highly contagious delta variant. For May, the CDC said the percentage of hospitalized patients who are vaccinated was less than 10 percent, but didn’t have a more specific figure.
As of Monday, Psaki said there would be no changes to Covid protocols around the White House where those who are vaccinated aren't required to wear a mask and that President Joe Biden would continue engaging with the pubic at impromptu stops and large gatherings.