Mice used for fetal tissue research are kept in the Humanized Mouse Core Laboratory at the University of California at Los Angeles. (Philip Cheung/For The Washington Post)

A senior scientist at a government biomedical research laboratory has been thwarted in his efforts to conduct experiments on possible treatments for the new coronavirus because of the Trump administration’s restrictions on research with human fetal tissue.

The scientist, Kim Hasenkrug, an immunologist at the National Institutes of Health’s Rocky Mountain Laboratories in Montana, has been appealing for nearly a month to top NIH officials, arguing that the pandemic warrants an exemption to a ban imposed last year prohibiting government researchers from using tissue from abortions in their work.

According to several researchers familiar with the situation, some of whom spoke on the condition of anonymity about the sensitive internal dispute, such experiments could be particularly fruitful. Just months ago, before the new coronavirus began to infect people around the world, other U.S. scientists made two highly relevant discoveries. They found that specialized mice could be transplanted with human fetal tissue that develops into lungs — the part of the body the new coronavirus invades. These “humanized mice,” they also found, could then be infected with coronaviruses to which ordinary mice are not susceptibleclosely related to the one that causes the new disease, covid-19.

Outside researchers said the scientists who created those mice have offered to give them to the Rocky Mountain Lab, which has access to the new virus that causes covid-19, so the mice could be infected with the source of the pandemic and experiments could be run on potential treatments. Candidates include an existing drug known to boost patients’ immune systems in other circumstances, as well as blood serum from patients recovering from covid-19.

“Kim Hasenkrug is one of the world experts in immune responses to persistent viral infection, including HIV and a whole bunch of other viruses,” said Irving Weissman, a leading stem cell researcher at Stanford University. In addition, the Montana NIH site has a biosafety lab equipped with high-level protections for experiments with dangerous microbes.

“It isn’t clear if this added layer of urgent investigations will find more effective” treatments for people infected in the pandemic than other approaches being tried, Weissman said, “but it’s stupid not to try.”

No therapies or vaccines for the new coronavirus exist yet.

The inability of the Montana lab, part of NIH’s National Institute of Allergy and Infectious Diseases, to pursue these experiments on the coronavirus is the latest example of disruptions to scientists’ work caused by the administration’s restrictions on research involving fetal tissue.

“When I hear the vice president saying [they’re] doing everything they can to find vaccines [and treatments], I know that is not true,” said one scientist familiar with the situation, referring to Vice President Pence’s daily news briefings of the White House’s coronavirus task force. “Anything we do at this point could save hundreds of thousands of lives. If you wait, it’s too late.”

Caitlin Oakley, a spokeswoman for the Department of Health and Human Services, which includes NIH, said, “no decision has been made” about Rocky Mountain’s request. She added that the administration’s “bold, decisive actions” to respond to the pandemic include “kick-starting the development of vaccines and therapeutics through every possible avenue.”

Hasenkrug has been forbidden by federal officials to talk publicly since the administration began to reconsider fetal tissue funding rules in the fall of 2018 at the prodding of social conservatives who oppose abortion and are part of President Trump’s political base.

The fetal tissue is donated by women undergoing elective abortions, and critics say that it is unethical to use the material and that taxpayer money should not be used for research that relies on abortion.

“Promoting the dignity of human life from conception to natural death is one of the very top priorities of President Trump’s administration,” HHS said in announcing its revised policy late last spring.

Under the policy Trump announced then, university researchers or other outside scientists face new restrictions on federal funding of such work. If an NIH grant proposal is approved through the normal scientific review process, it must then be evaluated by a new ethics advisory board that was announced months ago but does not yet exist. This winter, NIH officials officially invited nominations to the panel for the current year, but its members have not yet been determined, and no date has been set for it to convene.

The restrictions for government researchers such as Hasenkrug — known as NIH’s intramural scientists — are more severe. Those scientists have been banned from pursuing studies that involve fetal tissue. Hasenkrug was at the time of the ban collaborating on humanized mouse research aimed at a possible cure for HIV.

According to the scientists familiar with the events, a researcher at the University of North Carolina at Chapel Hill last month offered to send to Rocky Mountain nearly three dozen mice implanted with the human lung tissue that he and colleagues had recently shown could be infected with coronaviruses. There are enough of them for experiments with three or four potential treatments, the scientists said.

The offer came six months after the UNC scientists published their findings in the journal Nature Biotechnology about having succeeded in implanting human fetal lung tissue into mice with their own immune systems removed. The mice then grew human lung structures and were able to be infected with coronaviruses and other viruses to which mice ordinarily are not susceptible.

A senior UNC scientist, who has been cautioned by the university not to speak publicly about the research, according to other scientists familiar with the situation, did not respond to requests for comment.

On Feb. 19, two people said, Hasenkrug wrote to a senior NIH official, asking for permission to use those mice and run experiments related to covid-19. He eventually was told that his request had been passed on to senior HHS officials.

Since then, he has written repeatedly to NIH, laying out in greater detail the experiments he wants to undertake and why several alternatives to the fetal tissue-implanted mice would not be as useful. In one appeal to NIH, Hasenkrug wrote that the mice he was offered are more than a year old and have a relatively short time remaining to live, so they should be used quickly, according to Kerry Lavender, a Canadian researcher familiar with the correspondence.

Hasenkrug has not received an answer as to whether the administration will allow him to proceed, scientists familiar with his request said.

A person familiar with where things stand, speaking on the condition of anonymity about the internal dynamic, said the requests had been forwarded about two weeks ago to the White House’s Domestic Policy Council and that HHS and NIH were waiting for a decision there.

Late last week, Lavender, a former postdoctoral trainee at Rocky Mountain who helped develop a technique to implant mice with fetal tissue, heard from Hasenkrug, her mentor, asking whether she might undertake the coronavirus research that he was not allowed to do.

Lavender, an assistant professor at the University of Saskatchewan, said in an interview that she moved back to her native Canada less than two years ago because she wanted to continue pursuing fetal tissue studies and could see that the Trump administration was hostile to such research.

She said she is scrambling to try to carry out the experiments but is uncertain whether “we can pull it off. . . . I’m a new investigator with only so much funding,” she said, adding that she does not have immediate access to the kind of biohazard containment facility needed to do the work safely.

“If we were able to do this within the NIH, we would be able to do this much more quickly,” Lavender said. “Because the NIH budget all comes through the government, they can easily collaborate and fund what they are doing. . . . It’s much harder when we’re all separate entities to try to arrange the funding.”

According to one of the scientists, an experiment would take perhaps a week or 10 days to show whether a potential treatment was effective in the mice. Any promising therapy would then require testing in humans and approval by the U.S. Food and Drug Administration.

Stanford’s Weissman said one potential therapy that should be tried is a drug, already FDA-approved, that he developed initially for cancers that he and Hasenkrug more recently have found to be effective in boosting immune response in mice. People with weakened immune systems are particularly vulnerable to severe illness or death from covid-19.

“Will it work? We don’t know that,” Weissman said. But, he said, “this is a way to bring more minds and more hands” to the search for a treatment for the new pandemic.

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