White House coronavirus advisor Dr. Anthony Fauci said Tuesday that U.S. health officials are keeping an eye on a new strain of flu carried by pigs in China that has characteristics of the 2009 H1N1 virus and 1918 pandemic flu.
The virus, which scientists are calling "G4 EA H1N1," has not yet been shown to infect humans but it is exhibiting "reassortment capabilities," Fauci, director of the National Institute of Allergy and Infectious Diseases, told the Senate Health, Education, Labor and Pensions Committee during a hearing.
"In other words, when you get a brand new virus that turns out to be a pandemic virus it's either due to mutations and/or the reassortment or exchanges of genes," he told lawmakers. "And they're seeing virus in swine, in pigs now, that have characteristics of the 2009 H1N1, of the original 1918, which many of our flu viruses have remnants of that in it, as well as segments from other hosts, like swine."
The H1N1 swine flu and 1918 pandemic flu were both considered horrific viruses that spread across the globe.
The H1N1 swine flu emerged in Mexico in April 2009, infecting 60.8 million people in the United States alone and at least 700 million worldwide. An estimated 151,700 to 575,400 people died from the virus across the globe, according to the Centers for Disease Control and Prevention. It is now seen as one of a variety of seasonal flu viruses.
The 1918 flu, which Fauci has often compared to Covid-19, is estimated to have killed between 30 million and 50 million people, according to the CDC. More than 20 million people died in World War I, by comparison.
The new strain that is spreading in pig farms in China has been identified as having "all the essential hallmarks of a candidate pandemic virus," scientists say.
Fauci said Tuesday there's always "the possibility that you might have another swine flu-type outbreak as we had in 2009."
"It's something that still is in the stage of examination," he said. It's not "an immediate threat where you're seeing infections, but it's something we need to keep our eye on, just the way we did in 2009 with the emergence of the swine flu."
Fauci's comments came as the coronavirus continues to rapidly spread across the U.S., with the seven-day average of new cases growing by 5% or more in at least 40 states, including Arizona, Texas, Florida and Oklahoma, according to a CNBC analysis of data compiled by Johns Hopkins University.
Public health officials and physicians have criticized the Trump administration's lack of coordinated response to the virus. In recent weeks, President Donald Trump has downplayed the virus, saying the U.S. is nearing the end of the pandemic, contrary to experts in his own administration.
Earlier this month, Fauci said Covid-19 turned out to be his "worst nightmare" come to life as the coronavirus continues to rapidly spread across the globe.
He said the virus is "very different" from other outbreaks such as Ebola and HIV. The virus jumped from an animal host and has a high degree of transmissibility and mortality, he said. It is historically one of the worst pandemics the world has ever experienced, he said, adding people have compared it to the 1918 flu.
First detected in Wuhan, China, about six months ago, the new coronavirus has already infected more than 10.4 million people across the globe, killing more than 500,000.
On Tuesday, Fauci told lawmakers that he is concerned about the rise in new cases in places such as Texas and Florida.
He said reopening schools in the fall season will depend on the dynamics of the outbreak and the particular location of the school in question.