What People Can Learn From The Discovery Of A Polio Vaccine - NPR

What People Can Learn From The Discovery Of A Polio Vaccine - NPR
What to Expect When a Coronavirus Vaccine Finally Arrives - The New York Times
'Designer virus' is first new polio vaccine in 50 years - Medical Xpress

Posted: 21 May 2020 12:48 PM PDT

People in the 1950s anxiously waited for scientists to come up with ways to protect children from polio. The road to a polio vaccine might contain some lessons for today's health crisis.

ARI SHAPIRO, HOST:

Most health experts say a vaccine will be needed to end the COVID-19 pandemic. It wouldn't be the first time a vaccine ended a disease that terrorized Americans. In the 1950s, people waited anxiously for scientists to come up with a way to prevent children from coming down with infantile paralysis, better known as polio.

NPR's Joe Palca has the story of the bumpy road to a polio vaccine and the lessons it holds for today's health crisis.

JOE PALCA, BYLINE: There's something familiar about this newsreel footage.

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UNIDENTIFIED REPORTER: Here in Middletown, N.Y., a typical American town is caught in the fearful, silent grip of infantile paralysis. School closed because of polio. School closed.

DAVID OSHINSKY: There was - you know, there was a lot of anxiety.

PALCA: That's New York University Medical historian David Oshinsky, author of "Polio: An American Story." Unlike COVID-19, by the 1950s, polio was a familiar threat. Even former President Franklin D. Roosevelt had been stricken with it as a child.

OSHINSKY: So it'd been around for quite a while. And then certainly by the end of World War II, it had become a summer plague just sort of hitting the United States again and again and again at the same time of year.

PALCA: Then, as now, scientists felt a vaccine was the only way to end the epidemic. But Oshinsky says then, the government played very little role in coming up with one.

OSHINSKY: There was no federal research being done at this time. I mean, the NIH was this teeny, little organization, so it was basically up to a private charity to deal with this.

PALCA: The charity was the National Foundation for Infantile Paralysis, today known as the March of Dimes. There were several teams working on a vaccine, but the foundation focused on two. One was a more traditional vaccine being developed by a well-regarded virologist named Albert Sabin. Oshinsky says the other was a less studied approach using a virus killed with formaldehyde developed by a more junior scientist named Jonas Salk.

OSHINSKY: They gave both camps a lot of money, but it was clear that Salk's camp could produce the quicker vaccine.

PALCA: Millions of parents volunteered their children to be part of the March of Dimes' trial of the vaccine.

MARCIA MELDRUM: I don't even know if we could do this on (ph) polio vaccine trial today because I don't know if there's an organization that has the same level of trust.

PALCA: Marcia Meldrum is a social scientist at UCLA. The trial took place in the spring of 1954, and the vaccine was approved for distribution a year later.

MELDRUM: The public health service immediately licensed five different pharmaceutical firms to produce it. And one of them did not do a good job.

PALCA: Mysteriously, some children develop symptoms of polio after receiving the vaccine. It turned out there was a problem with the vaccine made by Cutter Laboratories. The company's manufacturing process did not fully kill the virus they used to make their vaccine. And as a result, hundreds of children who got the Cutter vaccine got polio, and some died. The debacle with the Cutter laboratory shattered public trust in the vaccine, though once the problem was identified and fixed, people started getting vaccinated again.

Historian David Oshinsky says the story of the Salk vaccine is one of the great success stories of American medical research.

OSHINSKY: Through the largest public health experiment in American history, they produced this remarkable result, but that in the end, you know, Cutter also tells you, you got to be cautious. You know, you can't do it too quickly.

PALCA: Joe Palca, NPR News.

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What to Expect When a Coronavirus Vaccine Finally Arrives - The New York Times

Posted: 21 May 2020 06:06 PM PDT

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On a spring morning in 1955, a pair of press officers greeted a mob of reporters in a stately hall on the University of Michigan campus. The officers had hot news: A clinical trial of the long-awaited polio vaccine had proved it to be safe and effective. The reporters nearly rioted in their scramble to spread the word. Once they did, church bells rang, and people ran into the streets to cheer.

In the midst of our current pandemic, collective hope for a vaccine is just as palpable and regularly reinforced — as it was with this week's news of promising results from a small coronavirus vaccine test. The federal government's top infectious-disease expert, Dr. Anthony Fauci, said that "the ultimate game changer in this will be a vaccine." President Trump assured us that a vaccine is not far off. Television hosts and pundits claim that this goal is within reach because we've beaten infectious killers, such as polio, with vaccines in the past.

But America's experience with polio should give us pause, not hope. The first effective polio vaccine followed decades of research and testing. Once fully tested, it was approved with record speed. Then there were life-threatening manufacturing problems. Distribution problems followed. Political fights broke out. After several years, enough Americans were vaccinated that cases plummeted — but they persisted in poor communities for over a decade. Polio's full story should make us wary of promises that we will soon have the coronavirus under control with a vaccine.

The first polio epidemic in the United States hit Vermont in 1894, killing 18 and leaving 58 permanently paralyzed. It was only the beginning. Over the next several decades, warm-weather outbreaks became common, striking communities one year and sparing them the next, sometimes only to return later with added force. A New York City outbreak killed more than 100 people in 1907. In 1916, polio returned and killed 6,000. The disease primarily struck children. It could kill up to 25 percent of the stricken. And it left many paralyzed, consigning some to life in an iron lung.

Scientists knew polio was caused by a virus but did not know how it spread. (We know now that it was spread by consumption of food or water contaminated by the virus in fecal matter.) Then, as now, the only way to stay safe was not to be infected. Towns with cases closed movie theaters, pools, amusement parks and summer camps. They canceled long-planned fairs and festivals. Parents kept children close to home. Those who could afford to do so fled to the country. Still, cases mounted. Among three early polio vaccines developed in the 1930s, two proved ineffective, another deadly.

Dr. Jonas Salk, who developed the polio vaccine, in his laboratory at the University of Pittsburgh. — Credit...Bettmann Archive, via Getty Images

Finally, in April 1954, a promising vaccine, developed by Jonas Salk's laboratory at the University of Pittsburgh, entered a large, yearlong clinical trial. On the day in 1955 when the press officers greeted the reporters in Ann Arbor, they shared the results: The vaccine, containing inactivated polio virus, was safe. It was also 80 percent to 90 percent effective in preventing polio.

The federal government licensed the vaccine within hours. Manufacturers hastened into production. A foundation promised to buy the first $9 million worth and provide it to the nation's first and second graders. A national campaign got underway.

But less than a month later, the effort ground to a halt. Officials reported six polio cases linked to a vaccine manufactured by Cutter Laboratories in Berkeley, Calif. The surgeon general asked Cutter to recall its lots. The National Institutes of Health asked all manufacturers to suspend production until they met new safety standards. Federal investigators found that Cutter had failed to completely kill the virus in some vaccine batches. The flawed vaccines caused more than 200 polio cases and 11 deaths.

The vaccine program partly restarted two months later, but more mayhem followed. With the vaccine in short supply, rumors spread of black markets and unscrupulous doctors charging exorbitant fees. One vaccine manufacturer planned to vaccinate its employees' children first, and then sent a letter to shareholders promising their children and grandchildren priority access, too.

States asked the federal government to create a program to ensure fair distribution. A Senate bill proposed making the vaccine free to all minors. A House bill proposed free vaccines only for children in need; according to newspaper accounts from the time, discussion of the bill triggered an "angry row" that forced the speaker to call a "cooling off" recess. The $30 million Polio Vaccination Assistance Act that President Dwight Eisenhower signed that August was a compromise that essentially let states decide for themselves.

Polio cases fell sharply over the next few years. Then in 1958, as national attention began to flag, cases ticked back up — among the unvaccinated. Polio cases clustered in urban areas, largely among poor people of color with limited health care access. States' "pattern of polio," government epidemiologists noted, had become "quite different from that generally seen in the past."

Three years later, the federal government approved an oral polio vaccine, developed by Albert Sabin's laboratory in Cincinnati, containing weakened, not inactivated, virus. By the end of that year, polio infections were down 90 percent from 1955 levels. In 1979, the country recorded its last community-transmitted case.

Credit...Bettmann Archive, via Getty Images

Today, decades into a global vaccination campaign, polio persists in just three countries. The battle against the disease has been a century-long march. And it has required a sustained commitment to continuing polio vaccination — a commitment now compromised as global polio vaccination efforts have been put on hold to slow the coronavirus's spread.

Granted, there are countless differences between the fight against the coronavirus and the long-ago fight against polio. The global capacity for vaccine research and development is far greater than it was in the 1950s. Drug approval and manufacturing safety protocols have been refined since then, too. Already, just months into the current pandemic, there are far more vaccines in development against the coronavirus than there ever were against polio.

But the regulatory thresholds we've spent decades putting into place are being swept aside to speed that development. And some of the coronavirus vaccines now in "lightning fast" development — by new biotech firms, university labs and familiar pharmaceutical giants — are as novel as the first polio vaccine was in 1955.

If one does prove safe and effective, we will face the same challenges we faced then — of making enough to protect the population, without causing harm, and distributing it without exacerbating existing inequities in our society.

Elena Conis is a historian and a professor in the Graduate School of Journalism at the University of California, Berkeley, where Michael McCoyd is a doctoral candidate in computer science and Jessie A. Moravek is a doctoral student in environmental science, policy and management.

The Times is committed to publishing a diversity of letters to the editor. We'd like to hear what you think about this or any of our articles. Here are some tips. And here's our email: letters@nytimes.com.

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'Designer virus' is first new polio vaccine in 50 years - Medical Xpress

Posted: 23 Apr 2020 10:24 AM PDT

Before being halted due to the COVID-19 pandemic, a relentless vaccination campaign had nearly succeeded in eradicating polio from the world. Between 2000 and 2017, the World Health Organization (WHO) estimated that its campaign had reduced the burden of the disease by 99 percent, preventing more than 13 million children from becoming infected and risking potentially debilitating paralysis.

But in recent years, the eradication effort has been plagued by outbreaks of vaccine-derived polio—in which the weakened virus used in oral polio vaccines evolved the ability to escape from vaccinated individuals and spread in communities with poor vaccination rates.

Now, with support from the Bill and Melinda Gates Foundation, UC San Francisco virologist Raul Andino, Ph.D. and Andrew Macadam, Ph.D., of the UK's National Institute for Biological Standards and Control (NIBSC) report promising Phase 1 clinical results for the first new oral polio vaccine in 50 years, which they have designed to be incapable of evolving the ability to cause disease in humans.

In a 2017 study, Andino and colleagues discovered that in every vaccine-derived polio outbreak they studied, the virus had used the same three evolutionary steps to mutate from harmless vaccine into a regional menace.

In their new study, published April 23, 2020 in Cell Host and Microbe, Andino, Macadam, and colleagues at the Gates Foundation, the Center for Vaccine Innovation and Access in Seattle, and the Centre for the Evaluation of Vaccination at the University of Antwerp have employed clever genetic wizardry based on decades of study of the poliovirus's biology to redesign the vaccine to ensure that is incapable of following this three-step pathway to re-evolve virulence. Specifically, they stabilized a region of the viral genome that is required for it to re-evolve the ability to infect humans, and ensured that the virus could not get rid of this modification even by exchanging genetic material with related viruses.

"To my knowledge, this is the first effort to rationally design a live attenuated virus based on detailed understanding on its biology, as opposed to the standard approach of blindly passaging the virus in animal cells to eliminate human virulence through poorly understood mechanisms," said Andino, a professor of microbiology and immunology at UCSF.

The new study presents results of a double blinded phase 1 clinical trial conducted in 15 adult volunteers at the University of Antwerp, all of whom had previously been vaccinated with an inactive vaccine composed of shredded virus particles to ensure they could not be made sick by the live vaccine.

The trial found that the new designer polio vaccine was both more stable and more effective than the 50-year old Sabin vaccine from which it was derived. Specifically, the new vaccine caused participants to generate plentiful antibodies against the poliovirus, and despite shedding viral particles in their stool, those particles were unable to infect or cause paralysis in mice. In contrast, previous studies have found that when mice are exposed to viral samples shed by people vaccinated with the standard Sabin oral polio vaccine, as many as 90 percent develop paralysis.

A phase 2 trial is currently underway and shows promise, Andino said, and the WHO is planning a phase 3 trial, hoping to fast-track development of the vaccine as an emergency measure to contain these outbreaks of vaccine-derived polio.

Applying Polio's Lessons to Search for COVID-19 Vaccine

In the wake of the suspension of the WHO's polio eradication efforts during the COVID-19 crisis, Andino's lab is now applying all they've learned designing polio vaccines to the search for new approaches for a SARS-CoV-2 vaccine, including developing a mouse model to better understand exactly how the virus spreads and causes disease.

Dozens of other COVID-19 vaccine efforts are going after the low-hanging fruit of traditional vaccination using isolated viral particles or more advanced RNA-based vaccination, but Andino is working to understand the biological pathways within the virus that might be most amenable to transformation into a safe but effective live attenuated vaccine that could be rapidly produced for worldwide distribution.

"I believe the lesson of polio is that it will take time to develop an optimal vaccine against SARS-CoV-2, and early efforts are likely to meet with unexpected challenges," Andino said. "Once we do have safe and effective vaccines, they'll need to be produced at global scale, which will probably require the use of older technologies that are already in place. Given how little we know about this new coronavirus, I'm betting we'll need all the weapons we can muster."

Explore further

Urgently needed: New way to combat vaccine-derived poliovirus

More information: Ming Te Yeh et al. Engineering the Live-Attenuated Polio Vaccine to Prevent Reversion to Virulence, Cell Host & Microbe (2020). DOI: 10.1016/j.chom.2020.04.003

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Citation: 'Designer virus' is first new polio vaccine in 50 years (2020, April 23) retrieved 22 May 2020 from https://medicalxpress.com/news/2020-04-virus-polio-vaccine-years.html

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