What most people call smallpox on this topic is three distinct things. There’s smallpox the disease. There’s the variola virus that causes smallpox. And then there is weaponized smallpox virus.
The virus could mean frozen samples, the 14kb of data or metric tonnes of physical material.
The WHO’s DNA sequence is NOT widely available. The sequence is tightly controlled by the WHO and researchers are not allowed to access more than a small percent of the whole sequence, I believe it’s 20%. Their copy isn’t that important except as potential disinformation vector.
Weaponized smallpox could just be “hot” strains. The Soviets ran a global campaign collecting particularly bad strains of any disease they could get their hands on. It was detailed in Alibek’s book Biohazard, although Alibek is not the most reliable source.
If a state is committed to hosting an offensive bioweapons program, they have also morally committed to the indiscriminate use of a weapon of mass causality. Richard Preston notes in his book The Daemon in the Freezer they’d likely be morally willing to test that strain on their own people, and down that slippery slope is a very low methodology that requires only very rudimentary science and zero ethics to optimize a new strain.
When the lead scientists in the Soviet bioweapons programs defected in 1993, we learned a lot about what they had been up to, which included field testing aerosolized versions of smallpox and producing metric tones for distribution by missiles. According to US intelligence, as late as 2021 the bioweapons program had survived despite attempts to destroy it due to careful efforts of Russias intelligence services across various political regimes. The current head of state is an intelligence officer, which eliminates those potential political conflicts.
Anyone who understands the extent of the Soviet program begins to understand why we likely won’t ever be able to say smallpox is eradicated with certainty.
The Soviets had an island complex for field testing in the Ural Sea called Aralsk-7. They had a documented bioweapon leak in July 1971 that resulted in an nearby outbreak. The outbreak was ended by a mass vaccination campaign, the suspension of all regional transport and (I think) mass quarantine. Occasional Paper 9 of the Center for Nonproliferation is a full report with commentary by relevant experts.
You conflate what would happen in a typical outbreak with what would be likely to happen in an biological attack. Since this weapon requires secrecy and can only be used once, an attacker would want to disperse a large amount at a night time event, or series of them. The bigger the event the better, the more events the better. Soviets optimized for the D50 value of the payload material required, which is the least amount of material needed to infect half the people in a one kilometer square.
Other factors that would tend to increase the impact of an attack would be if our national security apparatus and healthcare system was on the back foot―displaced or dismantled. Think: fire all the epidemiologists at the CDC level of crazy. If society had been primed with disinformation about masks and vaccines, that would aid the attack too.
If your argument is for pre-vaccination, JYNNEOS was specifically designed to be much safer than ACAM2000. In the wake of 9/11, a 2002 vaccination campaign to vaccinate healthcare workers lead by DA Henderson failed partly due to the fact that ACAM2000 is one of the most dangerous vaccines we have. ACAM2000 will only be used after an attack, and it is only available from HHS. Henderson has a page in his 2009 book that appears to describe deliberate stalling and sabotage of his 2002 campaign over paperwork for equipment manufactured in the ’50s regarding the number of needle jabs.
Henderson and Richard Preston were instrumental in the creation of the Strategic National Stockpile of mostly smallpox vaccines. Preston wrote the book that scared President Clinton in 1998, and when Henderson debriefed Soviet bioweapons scientists he immediately recognized the danger of a virus we had both zero immunity and zero production capacity for.
Smallpox is idiosyncratic as a virus because of how specialized it is in lethality and transmission pathways specific to humans. It simply cannot be compared with diseases like polio, measles, or anything we actively maintain heard immunity for, because we stopped vaccinating for it sixty years ago. Smallpox is way more contagious than ebola or anthrax.
Smallpox has a high reproductive number, six people become infected on average for every case, very similar to COVID. The global population has effectively zero immunity to it, also much like early COVID. Baring mass vaccination or sustained mass quarantines, the death toll would likely be near the case fatality rate multiplied by the susceptible global population.
For comparison, measles has a reproductive number of 20, so herd immunity level is 95%. The US maintains a vaccination rate around 93%, making the effective reproductive number around to 1.6 (very slow). Measles is only 1% fatal. So a full scale measles pandemic would be expected to kill 0.02% of the population in the US. If you repeat the above logic in a table for every disease, you will understand why no disease is remotely like smallpox in the potential for genocide.
On the range of lethality, with modern gene editing, inserting a single gene into a live virus is trivial and has been shown to cause drastic changes in vaccine resistance and lethality. This was discovered accidentally in a mouse/mousepox model by Ramshaw & Jackson.
Classical wild smallpox did have a one hundred percent kill rate on some Caribbean islands in the Americas during the genocides caused by European settlers. A weaponized smallpox strain developed with high lethality would tend to mutate back to the wild fatality rate in a pandemic, but it would likely become more contagious at the same time, as with COVID. The math for the end of a highly lethal outbreak is a bit wonky because the population changes drastically, increasing the concentration of people in a simple model.
For dated events in history, the Soviet Union has actively spread disinformation in about every major disease event since 1947, which usually center on rumors of an offensive US bioweapon program. It was the Soviet Union that proposed the global “eradication” of smallpox at the UN General Council in 1958 after a nine year absence. The US stopped vaccinating children in 1971. All major countries signed a bioweapon ban treaty in 1975. Access to ACAM2000 was restricted in the 1980s, no one was allowed to be vaccinated for smallpox, creating a totally naive population. Increased awareness around this specific threat coincided with the rise of anti-vaccine movement in 1998. There was a failed vaccine campaign (for HCPs) in 2002. In 2020-23 persistent COVID disinformation radically altered public views around masks and vaccines specifically. There were extensive efforts throughout 2025 into 2026 to actively dismantle both domestic and global public health, as well as our national counter-terrorism defenses. Specifically, the US DHS developed and maintained labs to monitor for pathogens at large events to give us a two week head start in response to an incident, and I believe those labs have been mothballed for the ICE roundup project. The rapid acquisition of concentration camps is obviously not good.
Hindsight is 20⁄20, and you were obviously wrong to get vaccinated in 2023, because we can all now agree you were too early.
It is scary, even if you’re vaccinated. Fear is great for motivating people, but not really great for getting people to act rationally in an emergency. Invoking terror would be part of the objective of the attack, and being clear headed and rational can mitigate the impact.
To think about what would happen in a disease event, you would want to know the Reproductive Number (R), the incubation period, and the fatality rate. I think those are about 6, 14 days and 30% respectively. Herd immunity would occur when around 5 in 6 people were had immunity, then the event would stop.
One case of smallpox would be an international emergency, but something that could be managed.
If a group managed to suspend CDC testing, and DHS monitoring, and infect a few million people, that scenario could ONLY be managed with mass quarantine.
DA Henderson wrote a guide for healthcare professionals for what to do in the event of a manageable smallpox bioterror event with more clinical information. Care would likely not take place in hospitals for very long. There is also a chapter on mass quarantine in the same issue.
On the fraction of DNA available, The WHO says:
https://iris.who.int/server/api/core/bitstreams/474cb0d6-76d1-42c1-a39b-e167b0e770ee/content
In Richard Preston’s The Demon in the Freezer, Superpox Chapter, he says it’s limited at 10%, but he wrote that book in 2002, and the current restrictions are from 2016.
The existence of the common DNA sequence with the WHO just will just give bad actors material for conspiracy theories and state propaganda narratives.
Yes, a little tongue-in-cheek. I think the jury is still out on how effective the JYNNEOS vaccine will turn out to be. A recent vaccine might presumably provide more protection, but it’s way better than not being vaccinated at all.
Even without vaccine, there is a lot of hope for managing an event with masks, handwashing and strict quarantine protocols. Good information (as well as disinformation) can travel much faster than a virus.