Yet some White House officials and experts worry those measures are insufficient and this weekend’s events may become another high-profile superspreader event, said three administration officials who spoke on the condition of anonymity because they were not authorized to discuss the issue. Behind the scenes, one prominent covid expert is scrapping with organizers hesitant to install devices that disinfect the air using ultraviolet light, with party planners worried the devices would interfere with the program.

Don Milton, a University of Maryland environmental scientist who has advised the White House and others on airborne transmission, said his offer to have a company install the devices at no charge was rebuffed by both the correspondents association and the Washington Hilton, which is hosting the event. “I enlisted a team of scientists and germicidal UV lighting companies to provide, as a demonstration project at no cost, a temporary installation to help protect the White House correspondents’ dinner,” Milton said. “Unfortunately, it has not worked out.”

In an interview, Steve Portnoy, a CBS News reporter who serves as the WHCA’s president, said the association had put safety protocols in place and Milton’s offer came too late.

“We’re interested in learning more about this technology,” Portnoy said. “We just aren’t in a position, with less than a week to go, to more fully understand the benefits or potential risks of what appears to be an experimental technology.”

The correspondents dinner arrives after weeks of debate over whether such events are still too risky as fast-spreading subvariants of omicron, like BA. 2, circle the globe — or if risking coronavirus is just one more hazard of normal life in 2022, given the expanding number of treatments to keep the virus from progressing to severe disease in most people.

The Gridiron Club outbreak “shows what living with covid-19 looks like,” Leana Wen, a Washington Post columnist, wrote earlier this month, saying that cases are inevitable and cheering that party’s return. “Nearly all of us will contract covid-19. Let’s prepare for when we do and resume living our lives in the meantime.”

But at least some individuals are choosing to bow out. Anthony S. Fauci, the president’s top medical adviser, has canceled his plans to attend the dinner, citing his personal risks, CNN first reported late Tuesday night. In an interview on Wednesday, the 81-year-old doctor said that it is his “personal choice” not to attend the event, even as he maintained the United States was moving past the “full-blown pandemic” phase of the virus.

As of Wednesday, the White House said that Biden, 79, planned to attend the dinner to indicate his support of the press.

Many covid experts say that new infections linked to the dinner and the accompanying parties are inevitable, noting that local cases have climbed, key officials such as Vice President Harris tested positive for coronavirus this week and the sheer number of attendees means that some infected people will unknowingly slip through the protections put in place. The correspondents’ association says it has sold 2,600 tickets to Saturday’s dinner.

“I think it is important for us to return to some of these activities — and to do it in a way that acknowledges the presence of the virus and the risks involved,” said Linsey Marr, a Virginia Tech engineer who has also advised the White House on covid strategy. Marr credited the WHCA for adding a requirement that attendees must produce evidence of a negative test on Saturday, but urged the association to go further to address airborne transmission of the virus.

“I hope they’re doing something to improve ventilation and filtration in the venue,” she said, noting that some guests like Biden face elevated risks because of their age and other factors. “There’s a non-negligible risk that he could become infected.”

The White House Correspondents’ Association dinner has been an annual rite of spring in Washington since 1921, albeit with occasional interruptions — most notably the cancellation of the dinner over the past two years due to the pandemic.

Despite its name, journalists comprise a minority of the guests at the black-tie affair. Attendees typically include people invited by media organizations, including advertisers, business executives, military officers, high-ranking government officials and friends of the well connected. Until former president Donald Trump boycotted the event, Hollywood celebrities and major sports figures often attended, lending some glamour to what has been self-deprecatingly nicknamed “the nerd prom.”

This year’s event is a return to form, with Biden and multiple media and political leaders slated to attend and comedian Trevor Noah set to deliver a post-dinner performance. But this weekend’s dinner features a new wrinkle, as invitees deliberate the risks of gathering en masse. While some people infected with coronavirus after the Gridiron Club dinner on April 2 had mild cases that quickly resolved, others experienced symptoms that lingered for days or weeks.

While the dinner will take place in the Washington Hilton’s cavernous ballroom, many attendees are expected to mingle in more confined spaces throughout the hotel, and attend numerous pre- and post-parties in close quarters, facilitating potential virus spread.

The Washington Hilton did not respond to specific questions about its current covid protections.

“The safety and security of our guests and team members remains our highest priority, and Washington Hilton remains diligent in our commitment to provide a safe, hospitable environment for all who visit our property,” a spokesperson said in a statement, touting the safety of prior events held at the hotel during the pandemic and referring questions about Saturday’s dinner to the correspondents’ association.

White House officials also referred questions about safety to the correspondents association, even as top officials sought to project a return to normalcy after two virus-ridden years.

“We are at a point in this pandemic … where I think we can gather safely,” Ashish Jha, the White House coronavirus coordinator, said on “Fox News Sunday” last week, noting how vaccines, testing and air filtration can reduce the risks associated with the virus. “I don’t think events like [the correspondents’ dinner] need to be canceled.”

Portnoy, the WHCA’s president, stressed that the association had taken multiple steps to ensure a safe evening.

“We are requiring that every person at the dinner takes a coronavirus test on Saturday, April 30, and shows [the negative result] to enter,” said Portnoy. Attendees also are required to be vaccinated, he said.

But Milton, the University of Maryland expert, urged the organizers to install more devices that actively clean the air for attendees.

“When you gather that many people together, you’ve really got to have highly effective air sanitation systems. Just ventilation and filtration aren’t enough,” Milton said.

After dozens of coronavirus infections were linked to the Gridiron Club dinner three weeks ago, Milton said he reached out to the correspondents’ association and arranged a conversation with a vendor, Far UV, that would have temporarily set up more than 100 devices at the Washington Hilton. Those work by disinfecting the air, and range from small devices that resemble smoke detectors to portable lamps that can be set up around a room.

But WHCA officials said the conversations with Milton and Far UV came too late in their planning, and that they feared the lights might irritate the eyes of attendees, interfere with servers trying to navigate the ballroom — and even make someone like Biden look blue when addressing the crowd.

In an interview, Milton said the technology had been proven, noting the White House last month touted the benefits of UV disinfecting light to fight covid.

“We’ve got really good data going back many decades,” Milton said, adding that he’d tried to convince the correspondents’ association about the devices’ value for weeks, although the group continued to decline the offers. “The reasoning is not clear to me,” he said.

PJ Piper, the president of Far UV, declined questions about his company’s conversations with the correspondents’ association, but said that school districts, the Department of Defense and other organizations had installed the devices. “To have an additional layer of protection that may be 10 times the equivalent air changes per hour that your HVAC could give you is a big deal. Because if the virus is not present in the air, you can’t catch it,” Piper said.

Other experts said the WHCA’s fears about the technology are groundless.

If installed correctly, UV disinfecting lights “can be used safely. They do not penetrate the skin. They don’t cause eye damage. They don’t affect photography,” said David Michaels, a George Washington University professor who led the Occupational Safety and Health Administration and has touted the technology’s potential, along with Milton. “It’s absolutely feasible” to install the lights before Saturday’s gala, Michaels added.

Michaels also rejected the framework that safety during the pandemic hinges only on individual steps such as getting vaccinated, wearing masks and getting tested. Instead, he argued that officials need to install more “passive” measures to protect the public, such as better air filters and UV lights to ensure that gatherings remain safe for attendees as well as the staff who work such events.

“We need to do more to protect people, before we can push the onus on them to protect themselves,” Michaels said.