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Medical workers return to work after recovering from coronavirus. But are they immune? No one knows for sure

Recovered staff generally protect themselves on the job as if they had no immunity

Physical therapist Lauren Detmer was greeted by applauding co-workers as she returned to work at Mass. General after being infected with coronavirus.Craig F. Walker/Globe Staff

Lauren Detmer, a front-line worker at Massachusetts General Hospital, returned to a hero’s welcome after being isolated at home for three weeks with COVID-19. Forty of her colleagues in green scrubs and blue masks lined a hospital hallway at 7:30 a.m. and, when she rounded the corner, erupted into applause.

But Detmer also finds herself in the center of a coronavirus medical puzzle: Are those who’ve recovered immune from future infections? Is COVID-19 like many other infectious diseases in that way? That question is particularly consequential for the hundreds of hospital workers returning to their jobs, many of whom head right back into caring for infected patients. Based on past experience with the flu and some other viruses, recovered COVID-19 victims might expect some immunity, but scientists said it’s too early to know if that is so — and how powerful or modest that protection might be.


"There are no answers right now,'' said Detmer, a physical therapist who works with patients in Mass. General’s ICUs, on her first day back. "I am going to pretend I never had it.''

So, she said, before heading into a patient’s room, she plans to carefully dress in full protective gear: a gown, gloves, N95 mask and face shield, just like her colleagues.

The plight of returning hospital workers has highlighted other unknowns about how hospitals screen for the potential contagiousness of this virus and make decisions about who can safely treat infected patients. The Centers for Disease Control and Prevention has two standards for when an infected health care worker is safe to return to work, so they won’t infect colleagues or patients.

Lauren Detmer said she'll continue using protective gear. "I am going to pretend I never had it," she said of COVID-19.Craig F. Walker/Globe Staff

Following one of those standards, some Massachusetts hospitals require that an employee be fever-free for three days, that their other symptoms have improved, and that seven days have passed since their first symptoms — a relatively easy hurdle to clear because it does not require testing. Partners HealthCare, which includes Mass. General, uses the stricter standard, which requires no fever and improved symptoms, plus two negative tests 24 hours apart. (The guidelines set by the CDC are even stricter for those working with patients with severely compromised immune systems, such as cancer patients; those workers also must wait two weeks from the onset of their symptoms before returning to their jobs.)


But leaning on test results has been problematic in its own way, offering puzzling and unpredictable readings that have delayed some employees’ returns.

Olivia Picking, a physician assistant in the Mass. General emergency department, got "pretty sick'' with COVID-19 and temporarily lost her sense of taste and smell — a common symptom of the disease. When she felt well enough to return, she got a negative test, then a positive test, and finally two consecutive negative tests. Infectious disease experts are not sure if these confusing situations are cases of faulty nasal swabbing, or whether infected people “shed” the virus intermittently.

Physical therapist Lauren Detmer displayed a photo of herself and her son while talking about her experience in quarantine.Craig F. Walker/Globe Staff/The Boston Globe

Raegan Thomas, a nurse at Brigham and Women’s Hospital, is still waiting to return to work after 30 days away. She got coronavirus last month after working in close quarters with a colleague who had also tested positive. She felt sick for a few days, but still well enough to do chores like laundry. Thomas also needs two negative tests before she can return to work — but she keeps testing positive, even though she no longer feels ill. Her only lingering symptom, Thomas said, is the loss of her sense of smell.


“I feel so guilty not being able to work,” she said. “I love being a nurse. It’s the most time I’ve ever had off, and I’m trapped in my tiny Boston apartment."

Once they are cleared to return, hospital employees interviewed by the Globe said, they are trying to protect themselves by proceeding as if they never had coronavirus. But despite the uncertainty, some feel emboldened by the presumption of immunity.

Dr. Justin Maykel, chief of colon and rectal surgery at UMass Memorial Medical Center, started feeling sick on a Sunday evening, March 22, and the next morning he tested positive for coronavirus. He spent the next several days at home in bed with fever, chills, muscle aches, headache, and a dry cough.

“I lost seven pounds,” he said. Maykel’s family — his wife and three teenagers — also became ill, though they didn’t qualify for tests to confirm they had coronavirus.

Maykel stayed home for two weeks. When he returned to work at the hospital, he felt ready to help his colleagues take care of COVID-19 patients. “Now that I’ve had it, I come to work with zero concern about contracting the virus,” he said. “We know how other viruses work, and we know how the immune system works. It’s logical that once you’ve had that virus and recover from it, you cannot get it again.”


Scientists are not so sure of that, because they don’t know enough yet about the specific workings of the coronavirus.

"That is the burning question,'' Dr. Duane Wesemann, an immunologist at Brigham and Women’s.

People get measles only once — or are protected by a vaccine. They generally get the flu once a season, but the flu mutates from year to year, so people get it again, he said.

"We can’t assume a particular virus is going to be in a particular category at this point,'' Wesemann said. "It’s a new virus, and we just don’t understand the immune response to it yet.''

While people who are infected generally develop antibodies to COVID-19, it’s unclear how much protection those antibodies offer, said Dr. Rochelle Walensky, chief of infectious diseases at Mass. General. Scientists are still studying how long any possible protection lasts, and if a person who had a severe case of COVID-19 has greater immunity than someone who had mild disease.

“The data that we have so far would suggest that this is like other respiratory illnesses, that those antibodies should be protective — but we haven’t proven that," said Dr. Helen Boucher, chief of geographic medicine and infectious diseases at Tufts Medical Center.

The Korea Centers for Disease Control and Prevention reported last week that a growing number of COVID-19 victims were relapsing, complicating the picture. Since those victims tested positive not long after recovering, officials said it was more likely that their original virus rebounded, rather than that they were reinfected by another person.


More than 9,000 health care workers in the United States had tested positive for coronavirus by April 9, according to the CDC. That represented 3 percent of total cases, but it’s likely a significant undercount because of gaps in testing data, CDC officials said, and more US health care workers are expected to become sick as the pandemic continues.

There is no full count of Massachusetts medical workers who have contracted the virus, but many major hospitals have reported significant numbers in the last five weeks. Mass. General has had 398 employees test positive for the coronavirus; the Brigham and Brigham and Women’s Faulkner Hospital, 274 employees; and Beth Israel Lahey Health, a 12-hospital system, 370 employees.

Hospital leaders believe most of those employees likely got infected through community spread, in part because workers who treat coronavirus patients wear head-to-toe protective equipment and because officials have not found clusters of infections in single units. But there is little data to prove whether the infections occurred in their line of work or elsewhere.

A wide range of hospital workers have become infected, not only nurses and doctors but also security guards and maintenance crew — who have little direct contact with patients.

Daniel Urizar,48, has worked in environmental services, helping keep Mass. General clean, for eight years and is now a supervisor. He and his wife, who also works at Mass. General, became sick, as did his in-laws. He worried that if he and his wife died, their two children would be left parentless.

“The part that hurt us the most was insulating our children in their rooms because of the small size of our apartment,” he said. "We also lasted 21 days of not being able to hug our children. Now ''we have come back 100 percent,'' said Urizar, who returned to work last Wednesday.

Detmer, the Mass. General physical therapist, isolated herself from her husband and 20-month-old son in her master bedroom. They left food outside her door, and she ran laps around her bedroom most days for 10 minutes. A test on April 4 was positive, but then a test six days later was negative.

She was tested again 24 hours later and checked her medical record for the results at 3 a.m. on Easter Sunday. Negative. She ran into the guest bedroom and awoke her husband to share the news. When she woke up her son that morning, he clung to her for 15 minutes.

Back at work, she was thrilled by the warm welcome from her colleagues, but aware of the risks.

“I don’t want to feel too comfortable,” she said. “I don’t want to make a mistake and bring it home to my family."

Liz Kowalczyk can be reached at Priyanka Dayal McCluskey can be reached at Follow her on Twitter @priyanka_dayal.