US has 100 million stockpiled doses that could protect against monkeypox

When Covid-19 hit, humanity faced an uncontrollable epidemic without vaccines or therapies. If it was a knife fight, we brought a pencil.

The level of preparedness for monkeypox couldn’t be more different.

“We have vaccines hidden away by our government,” said Blossom Damania, professor of microbiology and immunology at the University of North Carolina School of Medicine. “I don’t think people need to be alarmed. Monkeypox is a serious disease. We need to respect it and take it seriously, but we don’t need to panic.”

The United States keeps two Food and Drug Administration-approved smallpox vaccines in the Strategic National Stockpile — a product, in part, of a heightened fear of bioterrorism on 9/11. The monkeypox virus is similar enough that researchers expect both vaccines to offer protection, although only one, called Jynneos, has been approved by the FDA for use against monkeypox.

Centers for Disease Control and Prevention officials said Monday that more than 1,000 doses of Jynneos are in storage and can be distributed to those who have come into contact with infected people. In total, the government has more than 100 million doses of another smallpox vaccine called ACAM2000, CDC officials said.

Additionally, the FDA has also approved two treatments to treat smallpox, called TPOXX and Tembexa.

Image: A transmission electron micrograph of smallpox virus.
A transmission electron micrograph of the smallpox virus.Callista Images/Getty Images/Image Source

“Drugs that have been approved for smallpox have not yet been approved for monkeypox. But there is excellent data in the repositories for the licensing of these drugs where they have been tested against monkeypox. monkey in monkeys, and it works really well,” said Grant McFadden, director of the Biodesign Center for Immunotherapy, Vaccines and Virotherapy at Arizona State University.

The national stockpile includes doses of TPOXX, according to the FDA.

“Containing a monkeypox outbreak should be much less difficult than Covid-19,” said Dr. Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine and co-director of the Center for Vaccine Development in Texas. Children’s hospital. “We already have interventions.”

Smallpox spurred mankind’s first vaccines

The strain of monkeypox that has been reported in the United States and Europe has had a mortality rate of 1% in the past, according to the World Health Organization. In contrast, the deadliest form of smallpox killed around 30% of those who contracted it. It is therefore not surprising that smallpox stimulated some of the earliest vaccination practices in human history.

Researchers believe that centuries ago, people in Asia inhaled dried pustules of smallpox to cause mostly mild infections, thereby making them immune to serious diseases. The practice – called variolation – spread and took hold in England in the early 1700s.

In the late 18th century, Edward Jenner, a British physician, began developing the world’s first vaccine after observing immune protection in people who had contracted cowpox before being exposed to smallpox. His vaccine used cowpox to induce immunity against smallpox.

Later, safer smallpox vaccines based on other poxviruses were developed. After a worldwide campaign, the WHO in 1980 declared that smallpox had been eradicated – a public health triumph.

But fears that the virus could reappear because of a lab accident or a bio-attack remained. The terrorist attacks of September 11, 2001 heightened concerns, pushing the virus back into American minds and into the national budget.

“There was a lot of concern about bioweapons attacks on smallpox, especially after the anthrax attacks in 2000,” Hotez said. “We knew that the USSR had been working on weaponized smallpox for years.”

Since the turn of the millennium, the US government has spent more than $1 billion developing and stockpiling the Jynneos smallpox vaccine.

“The government has over one million doses of Jynneos, in frozen liquid form, in the National Strategic Stock or stored at our facilities in Europe,” said Paul Chaplin, president and CEO of Bavarian Nordic, the company company that manufactures the vaccine.

Just last week, Bavarian Nordic announced that the US government had exercised its contractual option to fill and complete an additional 13 million doses of freeze-dried Jynneos vaccine in the coming years. But the announcement was unrelated to the recent outbreak, Chaplin said: “It was completely coincidental.”

Jynneos is approved to treat smallpox in Europe under the name Imvanex. On Tuesday, French health authorities recommended it for adults who have come into contact with a confirmed case of monkeypox, including healthcare workers. Germany has also ordered the deployment of 40,000 doses of Imvanex if its outbreak worsens.

The vaccine is made from a modified, non-replicating form of vaccinia virus, which is in the same family as monkeypox and smallpox.

ACAM2000, which is made by Emergent BioSolutions, is based on a live vaccinia virus that can replicate. But this comes with a risk of side effects, especially for people with eczema or conditions that suppress their immune system. Thus, the non-replicating formulation of Jynneos may offer a safer option for people at increased risk of vaccine-related complications.

Monkeypox is not likely to mutate like the coronavirus

Monkeypox is not as contagious as smallpox and causes less severe illness.

“It’s much less pathogenic,” said Luis Sigal, a professor of microbiology and immunology at Thomas Jefferson University in Philadelphia who studies poxviruses.

Genetically, however, the two viruses are similar.

“Poxviruses are very highly conserved,” Sigal said. “In general, they have very little variation.”

This is why smallpox vaccines protect against monkeypox.

“You can vaccinate with one and get protection against another, and it’s very long-lasting protection,” Sigal said.

Dr Rosamund Lewis, head of the WHO’s smallpox secretariat, said previous research had shown that smallpox vaccines used decades ago “protected against monkeypox about 85% of the time”.

Smallpox vaccination
A scar from a smallpox vaccination is visible on the upper arm.Bernd Weißbrod/dpa/picture alliance via Getty Images

“We now have new vaccines because, although smallpox has been eradicated, research has continued over the past 40 years,” she added.

“I think you can stop this pretty quickly”

Unlike the coronavirus, monkeypox is associated with a telltale rash that should aid contact tracing efforts.

Also, the monkeypox virus does not mutate rapidly like a coronavirus. Coronaviruses are encoded in RNA, while poxviruses are DNA viruses. When DNA viruses replicate, they have more sophisticated proofreading components.

“DNA viruses are more stable,” said Damania of the University of North Carolina. “We’re not going to see all of these variants come out.”

But, she added, the fact that the public stopped getting the smallpox vaccine decades ago means more people are now susceptible to monkeypox. This could be a factor in recent outbreaks.

“It’s never happened where we have so many countries reporting outbreaks at the same time,” Damania said.

To quell new outbreaks of monkeypox, public health officials will likely look to the past. Smallpox was controlled by mass vaccination and with a so-called ring strategy, in which people who were in contact with people with smallpox were vaccinated.

“It can be done again with monkeypox,” said David Evans, a virologist at the University of Alberta. “As long as public health officials jump on it and come out and track down everyone these people have been in contact with, I think you can stop this pretty quickly.”

However, monkeypox is unlikely to be entirely extinct, as it can spread among rodents and occasionally spread to humans who interact with animals.

“The advantage of smallpox is that it’s one of the few viruses to have so much specificity for humans. There was no animal reservoir. Once the last person got sick, it didn’t there was nowhere left to catch the virus,” Sigal said. “You can’t vaccinate rodents.”

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