Polio vaccine could give temporary protection against COVID-19, scientists hope - NBC News

Posted: 11 Jun 2020 12:56 PM PDT

As the world waits for a coronavirus vaccine, some scientists are proposing that existing vaccines could give the body's immune system a much-needed temporary boost to stave off infection.

It's still unclear whether such an approach would work, and some experts are skeptical. Others — including researchers in Israel, the Netherlands and Australia — are already investigating whether a tuberculosis vaccine could help jump-start the immune system and make COVID-19 less deadly, though the World Health Organization strongly advises against using that vaccine until it's proven effective against the coronavirus.

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In the U.S., several big names in virology — including Dr. Robert Gallo, the director of the Institute of Human Virology at the University of Maryland School of Medicine and one of the scientists who discovered HIV — are turning their attention to another existing vaccine, the oral poliovirus vaccine. It hasn't been licensed or available in the U.S. since 2000, but is still used in other countries where poliovirus still circulates, according to the Centers for Disease Control and Prevention. (Polio was eradicated in the U.S. in 1979.)

June 10, 202001:06

In a perspective piece published Thursday in the journal Science, Gallo and other experts from the Baltimore-based Global Virus Network outline why this particular polio vaccine might hold potential — and why the group is seeking funding and approval to start clinical trials to test their hypothesis.

The polio vaccine in question is a live vaccine — meaning it uses a weakened form of the live virus.

Live vaccines trigger a general immune response that helps the body fight off invaders until the immune system has time to develop specific antibodies. In theory, scientists believe that this temporary immune boost could provide protection for viruses the vaccine was not designed to prevent, such as the coronavirus, said a co-author of the Science piece, Dr. Konstantin Chumakov, a member of the Global Virus Network, an international coalition of virologists aimed at preventing and eradicating virus disease.

(Chumakov is also associate director of research at the U.S. Food and Drug Administration's Office of Vaccines, but spoke to NBC News on behalf of the Global Virus Network, not the FDA.)

Using existing live vaccines, including the oral poliovirus vaccine, would not be a permanent solution, but rather a temporary fix that may buy time until a coronavirus vaccine hits the market, Chumakov said.

"The protection would wane with time, but the beginning of an outbreak is an important time to keep the virus from spreading," said Chumakov, noting that unlike the vaccine for tuberculosis, there are three types of oral poliovirus vaccine that could be administered back-to-back as soon as the immunity-boosting effects of one wears off, potentially extending such temporary protection.

The potential protection from the vaccine remains hypothetical, however, which is why Chumakov and others are calling for clinical trials.

In places where it's still used, the oral poliovirus vaccine is typically administered to babies and not adults, so scientists can't simply look at whether it already works to boost the immune system against other viruses in adults in these populations.

Chumakov referred to a three-year controlled trial conducted in Russia in the 1960s as the strongest evidence in support of using disease-specific vaccines to broadly ward off other viruses. In the study, which was conducted by Chumakov's mother, researchers concluded that giving adults doses of the oral poliovirus vaccine cut deaths due to seasonal influenza and acute respiratory diseases three-fold.

Chumakov and his co-authors also cite other studies and anecdotes in which an oral poliovirus vaccine has effectively prevented another strain of poliovirus, which the vaccine was not specifically designed to treat.

However, other experts in the field are skeptical that the polio vaccine would provide the needed boost, and view the existing research as flimsy at best.

"I do believe the oral polio vaccine would provide some protection against new viruses, but so would catching cold," said Rachel Roper, associate professor of microbiology and immunology at East Carolina University's Brody School of Medicine. Catching any virus, she said, would set up the antiviral state associated with enhanced immunity.

Roper also expressed concern that administering a live vaccine that does not specifically target COVID-19 could create competition — called immunodominance — that prompts the immune system to target the live vaccine while leaving few resources to fight off COVID-19.

"We won't see safety concerns until we test it in large trials that include a lot of people," Roper said.

Indeed, the oral polio vaccine shouldn't be given in an attempt to prevent COVID-19 outside of a clinical trial.

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Adam Lauring, an associate professor of microbiology, immunology and infectious diseases at the University of Michigan, said that if the oral poliovirus vaccine is proven to be effective, everyone would need to get the vaccine at the same time for it to work as planned, which would require a coordinated response with its own logistical challenges.

"There's also the issue of some people already having immune responses against some vaccines, which means this could impede some of the antibody responses we would want," said Lauring. In other words, the oral polio vaccine may not boost the immune system, as the theory proposes, in people who have already received a polio vaccine.

"It's a good idea, but we don't know how it would pan out. There is some epidemiological evidence that is a sign that it's something worth looking into," he said.

Chumakov estimates that it would cost $13 million to vaccinate the entire U.S. population, a relatively cheap solution if it works, and could provide a leg-up on future pandemics.

"This pandemic will go, but there will be another one. We will continue to get new and emerging diseases, and there will always be this dilemma of what do we do in the interim before we can develop a specific vaccine," Chumakov said. "This is much bigger than just stopping COVID-19."

CLARIFICATION (June 12, 2020, 12:12 p.m. ET): A previous version of this article omitted Dr. Robert Gallo's title. He is the director of the Institute of Human Virology at the University of Maryland School of Medicine.

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Among The 1st To Get A Polio Vaccine, Peter Salk Says Don't Rush A COVID-19 Shot - NPR

Posted: 30 May 2020 12:00 AM PDT

SCOTT SIMON, HOST:

As we wait for coronavirus vaccines, some Americans can still recall a time when polio terrorized the country every summer. Children were hit hardest, with thousands who were paralyzed or died. Frightened parents kept their children away from swimming pools, movie theaters and other public places. Nobody knows this story better than Peter Salk. He was one of the first to receive the polio vaccine. It was discovered by his father. NPR's Greg Myre spoke with him.

GREG MYRE, BYLINE: After years of research, Dr. Jonas Salk was just beginning to test a potential polio vaccine in 1953. He brought it home from his lab at the University of Pittsburgh and injected it into his three young sons. Peter Salk was the oldest at age 9.

PETER SALK: I just hated injections. And my father came home with polio vaccine and some syringes and needles that he sterilized on the kitchen stove by boiling in water, lined us kids up and then administered the vaccine.

MYRE: He wasn't old enough to fully understand why he and his brothers were getting this shot. Yet he remembers it like no other.

P SALK: As much as I hated injections, somehow, the needle must've missed a nerve. And I didn't feel it. And so that has fixed that moment in my mind.

MYRE: That moment also marked the beginning of the end of polio. Widespread testing followed. And two years later, the government declared the vaccine safe and effective against one of the most feared diseases in the country.

P SALK: What happened in the country at that moment was remarkable. There was jubilation. There was such a sense of relief that this fear, which had been hanging over everyone's heads for years and years and years, was finally lifted.

MYRE: It's one of the great vaccine success stories. And Jonas Salk became one of the most celebrated men in America. Peter Salk is now 76 and lives in La Jolla, Calf. He's also a doctor and a part-time professor of infectious diseases at the University of Pittsburgh, the same place his father did his groundbreaking work. Salk is optimistic about a COVID vaccine. But he's been staying at home the past couple months. And he cautions against racing ahead with a vaccine that hasn't been fully tested.

P SALK: What concerns me is knowing that, in the past, there have been unexpected things that have taken place with vaccines that had not been foreseen.

MYRE: Jonas Salk worked on his vaccine for seven years before it was approved. His research was funded by charitable donations. And the journalist Edward R. Murrow asked him about a patent for his discovery.

(SOUNDBITE OF ARCHIVED RECORDING)

EDWARD R MURROW: Who owns the patent on this vaccine?

JONAS SALK: The people, I would say. There is no patent. Could you patent the sun?

MYRE: Then, as now, the need to vaccinate was urgent. But there were delays, Peter Salk recalls.

P SALK: The vaccine was introduced but haltingly. It wasn't done the way my father would have liked to have seen. Let's just get this out and get it into every single child's arms.

MYRE: At this point in our conversation, Salk picked up a book and read a passage about this period. Some in Congress were impatient, he said. At one point, a government health official was called before a Senate committee. She was asked, why was it taking so long?

P SALK: (Reading) As to her failure to anticipate the need for adequate supplies of vaccine earlier than she did, she replied heatedly, I think no one could have foreseen the public demand.

MYRE: Peter Salk says it took roughly a decade for the polio vaccine to be researched, tested and distributed widely to the American public. He hopes it'll happen much faster this time. Greg Myre, NPR News, Washington.

(SOUNDBITE OF MUSIC)

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