Thread by @DrEricDing

Ever wonder why kids don’t get smallpox vaccine anymore? Because we once decided to eradicate it with #vaccines & 100% containment—& fully EXTINGUISHED smallpox off the face of the Earth 🌍. ➡️ We chose to go **ZERO SMALLPOX** because 500,000,000 deaths in 100 years was enough!!

2) So, was the smallpox vaccine some magical miracle 100% efficacy for a lifetime efficacy protection? No, it was 95% and for only 3-5 years, with waning after. It had to be used with contact tracing & village lockdowns to eradicate it—a PLUS strategy. health.ny.gov/publications/7…

3) The eradication of smallpox was no small feat. It took 10 full years to extinguish smallpox off the face of the planet. It was led by the legendary DA Henderson of @JohnsHopkinsSPH @CDCgov and @WHO.

His obituary was epic—by the great @helenbranswell. statnews.com/2016/08/21/d-a…

4) People said eradication was impossible. But “[Henderson] was a person of strong convictions,” said Foege, who served as director of the Centers for Disease Control and Prevention from 1977 to 1983 and who first met Henderson at the CDC in 1962.

5) “I always think that was one of the attributes that provided for leadership because people don’t like to follow someone who’s uncertain about where they’re going. He brought a certain certainty to everything he did.”— you had to if your mission was 100% smallpox eradication.

6) Before taking the lead in the smallpox eradication program, Henderson was the CDC’s director of disease surveillance. His mentor had been Alexander Langmuir, the epidemiologist who founded the CDC’s renowned program to train disease detectives.

7) “I remember with Alex once talking about a subject and he presented his side and I said: ‘But it’s worth looking at the other side,’” Foege recalled. “And he slammed his fist down on his desk and said: ‘There is no other side!’” 👀

8) “Like any war, the one against smallpox involved thousands of foot soldiers — notably outbreak tracers and vaccinators — & more than a few generals. They came from both the United States and Soviet Union, which first called for the disease’s elimination
nytimes.com/2016/08/22/us/…

9) “But, along with Dr. William H. Foege, Dr. Henderson was considered a field marshal whose combination of vision, bluntness, tenacity and political acumen carried the campaign to victory.”

10) Smallpox had been eliminated in much of the West shortly after World War II, but it persisted in Brazil, Africa and South Asia.

In 1966, he was sent to Geneva to run the World Health Organization’s global campaign.

11) “The sense at the W.H.O. was that this was an impossible mission, so they chose a young man who didn’t have a reputation to tarnish,” said Dr. Thomas V. Inglesby @T_Inglesby

(Translation—the wanted a “fall guy” in case it failed. That’s how un-confident WHO once was)

12) “I don’t want to say as cannon fodder, but something like that.”

World Health Organization campaigns to end yellow fever and malaria had both petered out, and the organization adopted the smallpox goal only after the Soviets and the Americans insisted, Dr. Foege said.

13) “D. A. always said they wanted an American to blame,” he added.

He was given little staff or support, but remaining on the C.D.C. payroll gave him independence.

➡️ He charged ahead anyway!!!

14) Dr. Henderson spent much of his time visiting smallpox-stricken countries, some of which were also caught up in civil wars. He filed detailed progress reports and threatened to quit when W.H.O. officials asked him to tone them down, Dr. @T_Inglesby said.

15) When the Soviets shipped weak vaccines, “he went to Moscow and confronted them.” 🔥

The campaign developed a freeze-dried vaccine that could withstand tropical heat and be given either with a compressed air “injection gun” or by putting a drop on a forked needle

16) Dr. Henderson quickly realized that trying to vaccinate vast populations was futile and switched to “ring vaccination.” It was “invented by accident” during a 1967 Nigerian outbreak when he had very little vaccine on hand.

17) “The first night, we asked ourselves what we would do if we were a virus bent on immortality,” he said. They radioed every local missionary asking them to send runners to find out which villages had cases.

18) They sent 80 percent of their vaccine to those villages, using it on the family of each case and all their recent contacts. The last 20 percent went to “anywhere we thought the virus would go next” — which was mostly to market towns where farmers and hunters sold their goods.

19) “It took D. A. about a year to come around to ring vaccination,” Dr. Lane, who worked with Dr. Foege, said. “But once he did, he was an enthusiastic proselytizer.”

20) The smallpox eradication campaign, many experts have noted, succeeded just in time (1977). A few years later, HIV spread across Africa. Because the live smallpox vaccine can grow in an immunocompromised into a huge, rotting, fatal lesion, you couldn’t use SP vaccine+HIV—WHEW!

21) To be clear—there were many involved in the eradication of smallpox besides Henderson and Foege and legions of WHO workers and local community workers. Also @larrybrilliant played a notable role as well in eradication in SE Asia. pandefense.com/larry-brilliant

22) Vaccines have been a miracle that have easily saved over a billion lives. We need to recognize how life saving they are. Some may have small side effects, but please don’t denigrate vaccines with conspiracies. That is unkind to your ancestors who survived because of them.

https://twitter.com/drericding/status/1501682259832811521

23) Finally, a shout out to @dawnymock who is the creator of this brilliant smallpox vaccine cartoon above ☝️ up top. dawnymock.com