Monkeys, ferrets offer needed clues in COVID-19 vaccine race

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VIDO-InterVac at the University of Saskatchewan

In this April 2014 photo provided by the Vaccine and Infectious Disease Organization-International Vaccine Centre at the University of Saskatchewan, a researcher holds a ferret at their facility in Saskatoon, Saskatchewan, Canada. In 2020, the lab is working with 300 ferrets developing a COVID-19 coronavirus vaccine candidate and testing other vaccine candidates and therapeutics. (VIDO-InterVac at the University of Saskatchewan via AP)

The global race for a COVID-19 vaccine boils down to some critical questions: How much must the shots rev up someone’s immune system to really work? And could revving it the wrong way cause harm?

Even as companies recruit tens of thousands of people for larger vaccine studies this summer, behind the scenes scientists still are testing ferrets, monkeys and other animals in hopes of clues to those basic questions — steps that in a pre-pandemic era would have been finished first.

“We are in essence doing a great experiment,” said Ralph Baric, a coronavirus expert at the University of North Carolina, Chapel Hill, whose lab is testing several vaccine candidates in animals.

The speed-up is necessary to try to stop a virus that has triggered a pandemic, killing more than 360,000 worldwide and shuttering economies. But “there’s no question there is more risk in the current strategy than what has ever been done before," Baric said.

The animal testing lets scientists see how the body reacts to vaccines in ways studies in people never can, said Kate Broderick, research chief at Inovio Pharmaceuticals.

With animals, “we’re able to perform autopsies and look specifically at their lung tissue and get a really deep dive in looking at how their lungs have reacted,” Broderick said.

She’s awaiting results from mice, ferrets and monkeys that are being exposed to the coronavirus after receiving Inovio’s vaccine. Since no species perfectly mimics human infection, testing a trio broadens the look at safety.

And there's some good news on the safety front as the first animal data from various research teams starts to trickle out. So far, there are no signs of a worrisome side effect called disease enhancement, which Dr. Anthony Fauci of the U.S. National Institutes of Health calls reassuring.