WASHINGTON — As the world grapples with a monkeypox outbreak, the Biden administration has been quick to highlight the vaccines and other therapies the United States has in its national stockpile. It’s been far less open about exactly how many of those medicines it has.
Right now, the country hasn’t seen many actual cases of monkeypox — only 40 confirmed cases as of Wednesday. But as global concern grows, officials are walking a tightrope, attempting to assuage public concerns while being cautious on both negotiations about sharing medicines abroad and what they say are national security issues.
The Biden administration is planning to make available stocks of two smallpox vaccines in response to the monkeypox outbreaks. Officials released some updated numbers on each of those vaccines Monday, even though they had previously told STAT on May 27 that the government does “not share specific numbers around vaccines due to security concerns.”
The government has 36,000 doses of the newest smallpox vaccine, made by Bavarian Nordic, on hand, with another 36,000 on the way this week, the pandemic office of the federal health department said. It’s a two-dose regimen, so that’s enough to vaccinate 36,000 people total.
Those numbers are only what the federal government immediately has in its possession, and don’t reflect the full scale of the possible response, an administration official said.
Ultimately, Bavarian Nordic has another 1 million doses that are owned by the United States and could be shipped, and supply for another more than 16 million doses that could be made into final vaccines. The vaccine, named Jynneos, is the only vaccine that the Food and Drug Administration has officially cleared for use against monkeypox.
Separately, the government also has 100 million of an older smallpox vaccine owned by Emergent BioSolutions immediately on hand, as well. That one hasn’t officially been cleared by the FDA for use related to monkeypox, but the Centers for Disease Control and Prevention has an expanded access protocol that allows it to be used for monkeypox, too.
But the public numbers don’t add up to the Biden administration’s statement in May that “the Strategic National Stockpile holds enough smallpox vaccine to vaccinate the entire U.S. population in the event of a smallpox emergency or monkeypox emergency.” The publicly disclosed doses total fewer than 101 million doses of smallpox vaccine, which would be enough to vaccinate less than one-third of the United States’ population.
An administration official declined to elaborate on which vaccines made up the additional more than 200 million doses that would be required to vaccinate the entire country. Before the two newest vaccines were approved, the United States had stocks of older vaccines.
The countermeasures that the United States has to prevent and treat monkeypox are also used for smallpox, a much more deadly and contagious threat. The only official stocks of the smallpox virus are kept in the United States and in Russia. Tensions have escalated between the two countries after Russia’s invasion of Ukraine earlier this year.
“Smallpox cannot be conflated with monkeypox. There is an exponential difference,” said a biodefense consultant.
The acute biological warfare threat from smallpox is part of the reason that the U.S. is so much better prepared for the monkeypox outbreak than it was for Covid-19.
“The biodefense dimension was weighted far too heavily compared with the flu pandemic possibility,” said Robert Handfield, a professor at North Carolina State University and an expert in the Strategic National Stockpile.
Traditional smallpox vaccines have significant safety risks that make a broad vaccination campaign a difficult tradeoff. Bavarian Nordic’s vaccine has a more favorable safety profile and can be used in immunocompromised patients.
“The risk and benefit is a double-edged sword. There’s a risk to people, and monkeypox, unlike smallpox, is nowhere near as deadly as smallpox,” the consultant said.
Treating people who’ve been exposed to monkeypox with antivirals is another potential option to address a monkeypox outbreak that would avoid putting otherwise healthy people at risk. However, the federal health department didn’t offer any details about what quantities of antivirals are available.
An administration official said the decision not to release data about antiviral stockpiles was made because fewer antivirals would be needed, as they are given after someone is infected.
However, Siga Technologies, the company that makes one of the smallpox antivirals, said in a July 2021 press release that the United States maintains a stockpile of 1.7 million doses. The federal government ordered another $7.5 million worth of the drug last month, according to a separate release. It’s not clear how many doses that order includes.
There is another antiviral developed to treat smallpox, but it isn’t currently available in the national stockpile, and it isn’t accessible for monkeypox yet. However, the Biden administration has started the process of ordering up to 1.7 million doses of the antiviral, and the CDC said it is developing expanded access to allow the drug to be used for monkeypox. The drug is in the process of being acquired by Emergent BioSolutions from Chimerix.
The Biden administration is also working to negotiate any international donations of monkeypox products, the administration official said. The United States was one of the countries that committed to send vaccine supplies to the World Health Organization’s joint international stockpile in case of a smallpox outbreak, according to a 2017 framework. France, Germany, New Zealand, the United Kingdom, and the U.S. collectively committed 31 million doses.
However, since this isn’t a smallpox outbreak, the calculations may be different. A Department of Health and Human Services spokesperson said that it is “premature to comment on what steps related to this previous commitment might be taken in the current situation.”
Bavarian Nordic has also delivered millions of smallpox vaccine doses over the past decade that are now technically expired. It’s unclear how many of those doses might have been destroyed. It could be possible to test the doses to see if they might still be effective even past their expiration date.
“Bavarian Nordic will work with the United States government to carry out potency testing for the doses of Jynneos in the U.S. stockpile that have exceeded their shelf lives as those requests are made,” a company spokesperson said.
The federal health department did not respond to an inquiry about whether it has requested any potency testing for smallpox vaccines.
This article has been updated to include information about a smallpox antiviral that is not currently available in the Strategic National Stockpile and to add additional detail about the safety profile of Bavarian Nordic’s smallpox vaccine.