Claim that Boston University created COVID-19 strain with an 80% kill rate omits important details

Social media lit up with news about what appeared to be an alarming study out of Boston University.

"Boston University CREATES a new COVID strain that has an 80% kill rate — echoing dangerous experiments feared to have started the pandemic," read an Oct. 17 Instagram post that showed a screen grab of a Daily Mail headline.

"A virus created in a lab? Where have I heard this before," read a caption with the post.

We found numerous social media posts that also shared the Daily Mail headline, all alluding to the unproven theory that COVID-19 was created in a Chinese lab. They were flagged as part of Facebook’s efforts to combat false news and misinformation on its News Feed. (Read more about our partnership with Facebook.) 

While scientists at Boston University’s National Emerging Infectious Diseases Laboratories did undertake research that involved creating a hybrid COVID-19 strain, the headline omitted important context about the purpose of the study, the safety measures undertaken during the study and its results.

The study, conducted in mice, reflected a common method for studying viruses and was not carried out dangerously, the university and other experts we spoke with said. What’s more, the study found that this hybrid strain was actually less fatal in mice than the original — not more.

Ronald Corley, director of the Boston University laboratory, said attention given to the 80% figure has been used to promote a "sensationalized" message.

"This was a statement taken out of context for the purposes of sensationalism," Corley said in a statement released by the university, "and it totally misrepresents not only the findings, but (also) the purpose of the study."

In the preprint study, which is not yet peer-reviewed, researchers at the Boston lab wanted to examine the spike protein in COVID-19’s original omicron variant, called Ba.1. Their aim was seeing whether the mutations in those proteins were the reason why the virus variant is milder than earlier COVID-19 strains and evades immunity more easily, but leads to fewer fatalities.

To do so, the researchers added a spike protein from omicron to an original strain of SARS-CoV-2 to create a new strain they called Omi-S. They then compared the effects that the virus’s new strain, ancestral strain and omicron strain had on infected mice.

All of the mice infected with the ancestral strain died.

All the mice infected with omicron survived. And 80% of the mice infected with Omi-S died.

Researchers concluded the results showed the lesser severity of omicron is not linked to the spike protein mutations. They said more research is needed.

The mice that were used were "a particular type of mouse that is highly susceptible," Corley said. 

"Consistent with studies published by others, this work shows that it is not the spike protein that drives omicron pathogenicity, but instead other viral proteins. Determination of those proteins will lead to better diagnostics and disease management strategies," said Mohsan Saeed, one of the study’s lead authors, in a statement provided by Boston University.

"Ultimately, this research will provide a public benefit by leading to better, targeted therapeutic interventions to help fight against future pandemics," the school’s statement said.

The headline shared in these posts derived from an Oct. 17 article in the U.K. news outlet the Daily Mail, which Boston University officials criticized as being misleading. The article, which has been updated with a new headline and additional critique of the study, quotes experts who said the research was an example of "gain-of-function" research, a broadly defined term about research that can potentially make a virus more dangerous.

But the school and other experts we spoke with rejected that assertion. They noted the work that was done in the Boston lab has been done elsewhere.

Featured Fact-check

Facebook posts

stated on April 9, 2024 in a Facebook post

Notice from a New Jersey doctor’s office proves that COVID-19 vaccines are dangerous for athletes.

Michael Imperiale, professor of microbiology and immunology at University of Michigan School of Medicine, said the Boston lab’s research could be considered "loss of function," because the new strain was less deadly than the original virus, which killed all the mice. He said it’s inappropriate to compare the Omi-S strain in this study with the original omicron strain, which killed none, because only the original strain was manipulated.

Andy Pekosz, a microbiology and immunology professor at Johns Hopkins Bloomberg School of Public Health, said the study’s work with COVID-19 is not unusual, pointing to two earlier similar studies.

"This is a common approach to map differences between two related lineages of SARS-CoV-2 and, in fact, it's done with many different viruses," Pekosz said. "By swapping large parts of the virus, you can determine more quickly which mutations might alter a virus’s fitness or replication."

Boston University also noted that the "research mirrors and reinforces the findings of other, similar research performed by other organizations, including the FDA."

Scientists at the U.S. Food and Drug Administration co-authored a similar study published in September.

The Boston research was conducted in the lab’s biosafety level 3 facilities, which allow researchers to work with dangerous pathogens. The lab is owned and operated by the school but it is part of a network of such sites around the U.S. where researchers can study infectious diseases.

Pekosz called the facility "a safe way to handle even the most dangerous of SARS-CoV-2 variants." 

Gigi Gronvall, a senior scholar at Johns Hopkins Bloomberg School of Public Health, said critics are ignoring the "extraordinary safety measures" taken in places such as the Boston lab, and that such research is vital.

"Safety comes first, but there is no indication that there was a safety problem," Gronvall said. "Understanding viruses like the one we are dealing with and which has killed millions requires, you know, studying it." 

Safety measures in the lab include a series of interlocked doors; sealed walls and floors; and sophisticated filtration and decontamination technology, according to the school.

But these labs aren’t risk-free, as a Vox article noted. It recalled a case of a lab worker in Taiwan being bitten with an infected mouse and later exposing the virus to more than 100 people.

In an interview with the health news site STAT, Emily Erbelding, director of the National Institute of Allergy and Infectious Diseases’ division of microbiology and infectious diseases, expressed misgivings that the Boston researchers did not alert the agency to the type of work being done.

"We wish that they would have," Erbelding said, though she also noted the media coverage overstated the risk of the work being done.

Boston University in its statement said it had no obligation to report its work to NIAID. The NIAID funded tools and platforms used in the research but did not fund the research directly, it said.

The research was approved by the Institutional Biosafety Committee and the Boston Public Health Commission, the school said.

We reached out to NIAID for comment but didn’t immediately hear back. But an NIAID spokesperson told the Financial Times that the agency was "examining the matter to determine whether the research conducted was subject to the NIH grants policy statement or met the criteria for review" under government research guidelines.

Dr. Anthony Fauci, NIAID’s director, said in an Oct 19 interview with CBS News that although the NIH did not fund the Boston study, "it was interpreted I think in an exaggerated way by some as being of great concern."

An Instagram post shared an image of a headline that read, "Boston University creates a new COVID strain that has an 80% kill rate."

This is partly accurate. Researchers at Boston University are investigating what made COVID-19’s omicron variant less deadly and more likely to evade immunity. In that effort, they added a spike protein from a milder omicron virus to an original strain of SARS-CoV-2 to create a new strain they called Omi-S. When researchers compared the effects of the three viruses on mice, they found that 80% of the Omi-S-infected mice died.

But citing the 80% figure alone leaves out key context, including that the resulting strain was less fatal than the original, which killed 100% of mice. Experts say this kind of research is not unusual and the experiment was conducted in accordance with accepted safety procedures. The mice used were highly susceptible to the virus. And the point of the study was to learn more about why the omicron variant of SARS-CoV-2 frequently evades immunity and leads to fewer fatalities.  

We rate this claim Half True.