In the war against bacteria, it’s time to call in the phages

Ella Balasa was 26 when she realized the routine medical treatments that supported her were no longer working. The petite lab assistant had lived since childhood with the side effects of cystic fibrosis, a hereditary disease that turns mucus in the lungs and other organs into a thick, sticky blob that gives pathogens a place to grow. To control infections, she was on a regimen of taking and inhaling antibiotics — but in early 2019, an antibiotic-resistant bacteria in her lungs made her sicker than ever before.

Balasa’s lung function had dropped to 18 percent. She had a fever and was too weak to raise her arms above her head. Even weeks of intravenous colistin, a brutal antibiotic of last resort, didn’t help. With nothing to lose, she asked a lab at Yale University if she could volunteer to receive the organisms they were investigating: viruses that attack bacteria, known as bacteriophages.

That January, Balasa rolled from her home in Virginia to New Haven, burdened with both an oxygen concentrator and doubts about whether the treatment could work. Every day for a week, she breathed in a fog of viruses that biologist Benjamin Chan, scientific director of Yale’s Center for Phage Biology and Therapy, had isolated for their attack capabilities. Pseudomonas aeruginosathe multidrug resistant insect that clogs Balasa’s lungs.

And it worked. The viruses entered the blob, attacked the bacteria and killed some of it; the rest of the bacteria weakened enough for antibiotics to knock them out. Balasa’s body cleared the life-threatening infection faster than ever before.

Today Balasa is 30; she still suffers from cystic fibrosis, but two more rounds of phages plus a change in medication have kept her from reliving the crisis that destroyed phage treatment. Now she consults with companies developing drugs for cystic fibrosis and works to visualize new treatments, including phages. “I very much think of them as a new way to treat infections,” she says. “If I hadn’t had access to phages, who knows what my life would be like?”

There is an asterisk behind her success: phages are unapproved drugs not only in the United States, but also in the United Kingdom and Western Europe. No company makes them for commercial sale in those countries, and hospitals and pharmacies don’t stock them. To administer them, doctors must apply for a compassionate use authorization from a government regulator—in Balasa’s case, the U.S. Food and Drug Administration—that shows their patients have no other options.

That process is inefficient and inherently unfair because it limits availability to those who are lucky and persistent and whose doctors have a strong professional network. Yet journal articles and researchers’ reports suggest that more than 100 patients in the US have received emergency phage treatments, mostly unpublished. Researchers are convinced that if phages were legally available, more lives could be saved.

And that could finally be the case. In 2021, the National Institutes of Health gave 12 US institutions $2.5 million for research into phage therapies. Last year, the NIH launched its first federally funded clinical trial of the beneficial viruses, supporting 16 centers to test safety and possible dosing levels against Pseudomonas, the pathogen that sickened Balasa. Other academic centers and private companies have launched about 20 trials in the US and about 30 in the UK and Europe. And in January, a committee of the British Parliament launched an investigation into whether phages could be marketed there.