Criticism and confusion have erupted following the Centers for Disease Control and Prevention’s abrupt recommendation last Thursday that fully vaccinated people can immediately shed masks in most settings. The agency is yet again on the defense over its mask guidance.

Mask usage has been one of the most contentious issues throughout the pandemic—and that seems unlikely to change anytime soon. Just last Tuesday, CDC Director Rochelle Walensky faced a grilling from Senate Republicans, who suggested that the agency was being too slow and too conservative in its health guidance, particularly on the issue of outdoor mask use.

At the time, the agency recommended that fully vaccinated people should continue to wear masks in many uncrowded indoor settings as well as in crowded outdoor settings. “We will continue to recommend this until widespread vaccination is achieved,” Walensky said in an April 27 briefing. On that day, around 29 percent of the US population was fully vaccinated.

In the Senate hearing on May 11, Republican Sen. Susan Collins was particularly critical of the agency’s stance, saying its guidance created “unnecessary barriers” for schools while “exaggerating the risks of outdoor transmission” and were “unworkable” for summer camps. Walensky stood by the CDC’s guidance.

Science under pressure

Two days later, on May 13, the agency stunned medical and public health experts by reversing course, saying that fully vaccinated people can shed their masks in nearly all indoor and outdoor settings, crowded or uncrowded, with the exceptions of healthcare settings and mass transit. At the time of the announcement last Thursday, about 35 percent of the US population was fully vaccinated. The percentage is currently up to 37 percent.

In a series of interviews on morning news shows this Sunday, Walensky again faced tough questions and defended the agency’s guidance, saying it was based on the latest science. She also denied that political pressure had anything to do with the agency’s 180-degree turn.

“I can tell you, it certainly would’ve been easier if the science had evolved a week earlier and I didn’t have to go to Congress making those statements,” she told Chris Wallace on Fox News Sunday, referring to her Senate testimony on May 11. “But,” she went on, “I’m delivering the science as the science is delivered to the medical journals and, you know, it evolved over this last week. The cases came down over this last two weeks and so I delivered it as soon as I can [sic] when we have that information available.”

The country’s tally of new daily cases has been in a steady decline since mid-April, when the seven-day average reached 70,000. That peak came after weeks of plateaued and slightly increasing case numbers, which raised the specter of a fourth surge. Now, average daily cases are down around 28,000.

As for the evolved science to back the mask update, Walensky pointed out four studies showing high vaccine efficacy in real-world settings and efficacy against coronavirus variants circulating in the US. Two of the studies were published in early May, while the other two came out on April 2 and April 28.

Walensky also noted a March 29 study that suggested that people with breakthrough COVID-19 infections after vaccination may pose less risk of spreading the virus because they carry lower amounts of virus in their respiratory tracts than unvaccinated COVID-19 patients. “These reduced viral loads hint at a potentially lower infectiousness, further contributing to vaccine effect on virus spread,” the study authors concluded. Lastly, Walensky highlighted an April 21 study in which vaccinated people with breakthrough COVID-19 infections in a skilled nursing home did not appear to have spread the infection onward in the facility.

Criticisms

Public health and medical experts have endorsed the CDC’s assertion that fully vaccinated people can safely go maskless for the most part. However, they roundly criticized the timing and delivery of the announcement. Among the criticisms is that the percentage of fully vaccinated people in the US is still rather low, not the “widespread” threshold Walensky had previously suggested. Also, many adults have not yet had enough time to achieve full vaccination since vaccine eligibility opened up last month. And vaccination among 12- to 15-year-olds has only just begun.

Others said the agency should have given people more notice to prepare for the lifting of mask restrictions, plus disease burden benchmarks to guide the timing for easing restrictions.

A critical point of confusion and frustration is that there’s no sure-fire way to determine someone’s vaccination status—thus, there’s no way to enforce any remaining mask requirements for unvaccinated people. Many have suggested that the new guidance puts businesses and employers in an even more difficult position than before.

“Millions of Americans are doing the right thing and getting vaccinated, but essential workers are still forced to play mask police for shoppers who are unvaccinated and refuse to follow local COVID safety measures. Are they now supposed to become the vaccination police?” Marc Perrone, president of the United Food and Commercial Workers union, said in a statement.

Meanwhile, medical experts have ticked off reasons why some fully vaccinated people may still want to keep their masks on for now, including the risk of breakthrough infections—which is low but not non-existent. There’s also concern among fully vaccinated people who are often around vulnerable and/or unvaccinated people, such as young children and immunocompromised people. The question of waning immunity over time and concern about variants further complicate the equation. Adding to all of this worry is the news that eight fully vaccinated members of the New York Yankees tested positive for the coronavirus last week.

Walensky has told reporters that the agency will continue to update guidance documents. In an interview Sunday on CBS News’ Face the Nation, top infectious disease expert Anthony Fauci suggested that the agency would likely refine its current guidance on masks.

“I would imagine within a period of just a couple of weeks, you’re going to start to see significant clarification of some of the actually understandable and reasonable questions that people are asking,” he said.

https://arstechnica.com/?p=1765479