Impact of Vaccines; Health, Economic and Social Perspectives
The Global Monkeypox Outbreak
The Johns Hopkins briefing
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The following Johns Hopkins experts participated in the briefing:
New Countries Stockpile Antiviral TPOXX As Monkeypox Outbreak Continues
pharmaphorum editor in chief Jonah Comstock talks to Philip Gomez, CEO of Siga Technologies, about how his company's antiviral drug can play a crucial role in addressing monkeypox cases.
Although the World Health Organization is still rating the current monkeypox outbreak as a moderate threat, the disease has continued to spread, with 2,103 cases in 42 countries and one confirmed death, according to the latest WHO data.
Accordingly, countries around the world are gearing up to address the outbreak. Yesterday, SIGA Technologies, makers of the antiviral drug TPOXX (tecovirimat), announced that it has received $13 million in procurement orders for the drug, including two new international jurisdictions and an approximate $2 million order from a country with an established contract with the company.
"Before the monkeypox outbreak, really, only the US and Canada had stockpiled our drug and very few people had actually stockpiled the vaccine between Canada, the US, and a few other countries," Siga CEO Phil Gomez told pharmaphorum. "So not a lot of people were prepared for this, even though there's been a lot of discussions over the years that this family of viruses is very deadly and everyone should have product."
TPOXX is approved in Europe for the treatment of monkeypox and in the US and elsewhere for the treatment of smallpox, but can be prescribed off-label. One of the new countries stockpiling the drug is in Europe. The other, and the existing customer, are in the Asia-Pacific region, according to the company.
The orthopox threat
Monkeypox is a part of the orthopox family of viruses, which also includes smallpox, a deadly and contagious disease that was irradicated in the 1980s in an unprecedented immunisation campaign. Monkeypox is both less contagious and less deadly than smallpox, with the West African clade (the version of the virus involved in the current outbreak) having an estimated 1% fatality rate in humans.
The vaccines used to irradicate smallpox also offer some protection from other orthopox viruses, which might be one reason that the virus has rarely spread outside of Africa before this outbreak. But smallpox vaccination was halted in 1980, so the portion of the population with that crossover immunity is dwindling.
"I was at the US National Institutes of Health, at the National Institute of Allergy and Infectious Disease, a place called the Vaccine Research Center," Gomez said. "I was part of the team that worked on the first SARS vaccine that went into humans. And I think what we've learned post-COVID … is we should think about families of viruses and the threats they may pose. So when I worked on that SARS vaccine, we probably should have developed a pan-coronavirus vaccine rather than SARS or MERS. Because then we had COVID-19. And the orthopox family viruses is one of those families that we've been worried about for a long time, because smallpox is in that family."
In the case of monkeypox, it is still not clear what factors are behind this outbreak.
"If you talk to public health experts, they've always been worried about this because either the virus started to transmit person to person because we happened to hit a population that had close contact, or the virus evolved and became more transmissible. And so I think in this outbreak, people are leaning towards the former. But to be honest, we got to wait for the data to come out and understand why it does seem to be behaving differently," Gomez said.
Vaccines and antivirals
One thing that makes monkeypox very different from COVID-19 is that it appears to have a much longer asymptomatic incubation period. This means that even though there is a vaccine for monkeypox, and several smallpox vaccines effective against monkeypox, it's a challenge to stay ahead of the infection chains with vaccination.
"Monkeypox is about one to two weeks where the person doesn't know that they've been infected," Gomez said. "Obviously, the vaccine is effective if given prior to infection or even within the first days of infection. But once they progress and show up with symptoms, really the only thing that will mitigate the impact is an antiviral drug."
TPOXX not only helps with symptoms and survivability, it also reduces patients' viral load, making them less likely to infect others.
"So, one of the discussions is, as part of this outbreak, should we be giving an antiviral drug to people who may have been exposed?" Gomez said. "And we actually have been examining that for a number of years through the support of an R&D grant from the US military, where we actually give drug and vaccine to people at the same time. The vaccine would protect them long term and the drug would immediately both protect them and if they had it, and potentially reduce their infectivity."
As evidenced by yesterday's news, countries are stockpiling both vaccines and TPOXX, and attempting to contain the outbreak through contact tracing and ring vaccination.
"Many people, and I think even the US government's initial reaction was vaccines, vaccines, vaccines," Gomez said. "And I've worked in vaccines my whole career, so I totally believe in that. In this outbreak, though, it really is going to be the interplay of antiviral drugs and vaccines that potentially are the toolset that helps us stop some of this transmission, make sure that people don't have severe disease, and hopefully reduce the outbreak."
Yes, A Smallpox Vaccine Protects Against Monkeypox, But It Comes With Its Own Set Of Risks
Google searches for "smallpox vaccine" have rocketed since monkeypox cases started turning up in people across Europe and North America who have no recent travel history to Africa.
The search curiosity is not unprompted — President Joe Biden promoted the US' smallpox vaccine stockpile when he told reporters on Monday he doesn't think the monkeypox outbreak merits the same level of concern as COVID-19.
"Look, we've had this monkeypox … in the past," Biden said, referring to an outbreak that occurred across six states and infected dozens of people in 2003.
"The smallpox vaccine works for it."
However, while a smallpox vaccine may be around 85% cross-protective against monkeypox, not everyone can just run to their local pharmacy and get a shot right now.
There are two smallpox vaccines in the US. For the newer, safer one, supply is scarce — representatives from the Centers for Disease Control and Prevention said on Monday that upwards of 1,000 doses of the Jynneos vaccine are available right now, and that "we expect that level to ramp up very quickly in the coming weeks."
The US has also stockpiled more than 100 million doses of another, older smallpox vaccine, called ACAM2000, but infectious disease experts warn it carries a higher risk of heart problems, brain swelling, blindness, and in the most severe cases (one in a million) — death.
Eradicating smallpox may have had 'unintended consequences' for monkeypox Models line up for their smallpox vaccinations in October 1955. FPG/Hulton Archive/Getty ImagesRoutine smallpox vaccination was stopped in the US in 1972, more than 30 years after the last smallpox cases were diagnosed in the country. In 1980, smallpox was declared eradicated worldwide — it's the only human disease that vaccines have successfully wiped off the planet entirely.
Babies today aren't vaccinated against smallpox, and the last people vaccinated in large numbers are around 50 years old, or older. (You can see tell-tale signs that some older adults had a smallpox vaccine, because they have characteristic scars on their arms.)
A doctor points to a patient's scars from a smallpox vaccination on December 16, 2002 in Florida. Chris Livingston/Getty ImagesWhile the eradication of smallpox through vaccination has saved more than 200 million lives and many billions of dollars over the past four decades, infectious disease experts have been warning for several years now that the lack of vaccine-induced immunity to smallpox worldwide may carry some "unintended consequences."
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It's estimated that roughly 70% of the world has no immunity to smallpox today, and experts suspect that may be at least part of the reason why monkeypox outbreaks have become more common in some western African countries, like Nigeria, in recent years.
Older smallpox vaccines leave scars, and carry risks of spreading the disease A smallpox vaccine is administered to a sailor on a ship off the coast of Djibouti in 2003. Sean Gallup/Getty ImagesThe US keeps a strategic national stockpile of smallpox vaccine on hand at all times, just in case of a bioterror attack, but during peacetime the CDC only recommends the smallpox vaccine to lab workers who work with smallpox, or smallpox-like orthopoxviruses, including monkeypox.
According to the CDC, there are enough vaccines to vaccinate "everyone who would need it" if a smallpox disaster occurred. (Unlike COVID-19 vaccines, if you take a smallpox vaccine in the week after you're exposed to the virus, it can still offer some protection.) But the US's national stockpile includes many doses of the older, more dangerous ACAM2000 vaccine, which experts are understandably cautious about taking off the shelf unless it is absolutely necessary.
The UK — where the first monkeypox case of the 2022 outbreak was announced on May 7 — also uses the newer, safer smallpox vaccine from Bavarian Nordic (called Jynneos in the US) but in Europe it's referred to as Imvanex. (The UK began offering Imvanex to healthcare workers that may have been exposed to the virus on May 20.)
Infectious disease expert Andrea McCollum, who investigates monkeypox outbreaks for the CDC, said she decided to get vaccinated with ACAM2000 because it was recommended for her work, at a time when the newer, safer Jynneos vaccine wasn't available yet.
"I felt as if the benefit of vaccination far outweighed any risk associated with handling specimens, not vaccinated," she told Insider.
ACAM2000 is a live virus vaccine (Jynneos is not) and as such it prompts a smallpox-like "pock" to form on the arm, in the days after it is injected.
"With ACAM2000 you do develop, it's called a 'take,' you develop the lesion on the arm — it's an indication of successful vaccination," McCollum said.
For her, it wasn't a big deal, because she knew what to expect — feeling "crummy" for a "couple days" — and she knew how to take care of the blister, which scabs, falls off, and eventually leaves a small scar.
"It has to remain covered, and you have to do frequent handwashing and appropriately take care of the site and any of the bandages," to avoid infecting others in the roughly three weeks after vaccination, McCollum said.
Correction: A previous version of this story mistakenly said that Imvanex and Jynneos are different vaccines — they are not, they are just different brand names for the same product in the US and Europe.
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