News Release

McMaster-led trial reduces COVID-19 hospitalization risk with single injection

Pegylated interferon lambda can successfully treat COVID-19 in people early in the disease

Peer-Reviewed Publication

McMaster University

Hamilton, ON (Feb. 10, 2023) – A team led by McMaster University researchers Gilmar Reis and Edward Mills has discovered that a single injection of pegylated interferon lambda (lambda) can successfully treat COVID-19 in people early in the disease.


They say that one dose of lambda injected under a patient’s skin was more effective than any currently available treatment for early COVID and avoids the potential problems of patient adherence to drug treatment regimens.


The findings were published in The New England Journal of Medicine on Feb. 9.


“This discovery allows us to enter a new era where you can have pan-virus interventions against a range of diseases,” said Mills, a professor of the Department of Health Research Methods, Evidence, and Impact (HEI).


Reis, an associate professor of the HEI, said, “Pegylated interferon lambda is a safe drug, and it is a single treatment approach.”


“Lambda is not virus-specific as it works on all the different COVID-19 variants, and it probably also has a role to play in combatting other respiratory viruses such as influenza. We are beginning a study now of lambda for influenza.”


Researchers tested lambda’s effectiveness using a randomized placebo-controlled trial involving adults with COVID-19 from both Canada and Brazil, who freely volunteered for the study. A total of 931 people received lambda and 1,018 received a placebo. Eighty-three per cent of the trial participants were vaccinated. Researchers ran the lambda trial from June 2021 to March 2022.


Lambda works by activating the immune system’s antiviral defences against COVID-19 viruses invading the airways. Among the mostly vaccinated trial participants, lambda significantly reduced the need for hospitalization or emergency room visits compared to the placebo.


“This could save tens of thousands of lives,” said Mills.


Reis said, “The ultimate aim would be using it in combination with Paxlovid, but that needs to be evaluated in a clinical trial setting.”


The lambda research falls under the ongoing TOGETHER trial, which Reis and Mills have led since June 2020. The ongoing platform study has evaluated multiple potential COVID-19 treatments during the pandemic. Potential treatments are always evaluated against a placebo.


The TOGETHER platform has to date evaluated 14 different potential treatments, including lambda, since it was first launched in June 2020.


External funding for the study was provided by FastGrants and the Rainwater Charitable Foundation. The lambda used in the trial was provided for free by Eiger BioPharmaceuticals.


The McMaster researchers involved with the trial were Gilmar Reis, Edward Mills, Paula McKay, Sheila Sprague, Lehana Thabane and Gordon Guyatt.

The study was done in partnership with Jordan Feld at University Health Network (UHN) and Professor Jeffrey Glenn at Stanford University. 





A photo of Peginterferon Lambda can be found here:

Credit: UHN



For more information, please contact: 

Veronica McGuire 

Media Relations 

Faculty of Health Sciences 

McMaster University 



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