But vaccines won’t help if folks don’t know how to use them correctly, or can’t.
Others avoid vaccines because they believe warnings from dubious sources.
- Facts and fears
- In the news
- Remembering ‘simpler times’
Being healthy isn’t a mark of holiness. Neither is being sick. What counts is how we deal with what we’ve got. There’s a great deal more to say about that, but not today. (Catechism of the Catholic Church, 828, 1509, 2211, 2288–2291, 2292–2296, 2448)
We’re reasonably sure that folks have been getting polio for millennia. Polio epidemics weren’t a problem until 1907.
I could blame the 1907 outbreak on the American Congress. They passed the Pure Food and Drug Act in 1906.
I think that was a good idea. But let’s say that I don’t, and have ‘old fashioned values.’ (October 16, 2016)
Applying an earlier century’s all-to-common spin on Christianity, I could claim that food poisoning “is a visitation from God.”
The early, and mid, 20th century had it’s oddball notions too. We’ve got a slightly different set today. They make just as much — or little — sense.
The last time a case of polio started in my country was in 1979.
Polio hasn’t been eradicated yet, so someone could catch the disease before entering the United States. That hasn’t happened since 1993,1 but I think routine vaccinations are still a good idea.
Polio isn’t the only serious disease, of course. But apparently some folks remember that it’s something to avoid. That makes sense. Panic? Not so much.
Researching this post, I learned about what one outfit called the “The Great U.S. Polio Panic of 2015.”
The disease acted like polio, but wasn’t. Several enterovirus D68 cases had been diagnosed, mostly in the Midwest, in 2014. I missed that “panic,” so it may have been limited to folks with specific reading preferences.
When I finally started walking, it was with a limp. I’ve talked about hip dysplasia, doctors, and why I take medical ethics a bit personally, before. (October 7, 2016)
This was the 1950s, so at least one person figured I’d survived a polio infection. It was a reasonable guess at the time.
Folks my age are among the last Americans whose parents might have reasonably feared another polio epidemic.
Polio epidemics started in the 20th century.2 The disease is much older.
Now that we know what to look for, scientists and historians have traced polio back several millennia.
I’ll grant that a retrospective diagnosis on someone who died three millennia back can be debatable. And often is. Debated, that is.
But we do have pictures. I think it’s likely that the priest pictured on that stele had polio, and survived.
Something left him with a severely deformed left foot. A little over 32 centuries later, we’re reasonably sure that he had polio: or something that acted like polio.
The first clinical description of poliomyelitis, polio, was published in 1789. That’s when Michael Underwood described “a debility of the lower extremities.”
The disease had quite a few names in my language during the early 19th century: Dental Paralysis, Infantile Spinal Paralysis, Essential Paralysis of Children, Regressive Paralysis, Myelitis of the Anterior Horns, Tephromyelitis, and Paralysis of the Morning.
Jakob Heine wrote a medical report on Lähmungszustände der unteren Extremitäten in 1840. It’s pretty clear that the “paralysis of the lower extremities” he described was polio.
The disease wasn’t common. Outbreaks were scattered and small. We didn’t have polio epidemics before the 20th century. (August 21, 2016)
Some died because paralysis hit systems we use to breathe. By the 1950s, we’d figured out how to keep folks who couldn’t breathe on their own alive with tech like iron lungs.
It was an improvement on the ‘good old days,’ but not by much.
In 1952 the first practical polio vaccine was developed in a lab.
We’d learned, the hard way, that careful testing makes sense. I’ll get back to that.
Nobody died this time around, and the vaccine worked. Mass inoculations started in 1955. An average of about 20,000 folks were catching polio each year by then.
I went through an immunization sequence, and didn’t mind at all when an oral vaccine replaced injections.
Elections started a few revolts later. Women couldn’t vote, and the Política dos Governadores made sure unsuitable candidates didn’t get elected.
It wasn’t all bad news. President Francisco de Paula Rodrigues Alves apparently thought smallpox inoculations would be a good idea. I think he was right about that.
However, if half of what I’ve read about the program is accurate, it could be a case study in how not to conduct a public immunization program.
The 1904 Rio de Jainero ‘Vaccine Revolt’ was the high, or low, point.
Depending on who you believed, folks like the chap wielding a scalpel in that cartoon were to blame; or the broom-and-hatchet brigade.
My guess is that official attitudes hadn’t changed much since 1891, when the Inspector of Public Health reported that Rio promoted a “complete absence of moral virtue” among its inhabitants, who practiced “horrendous nudity and licentious behavior.”
A much more recent, and academic, publication’s author says that the problem was clashing cultural norms.
Government doctors didn’t see a problem with going into someone’s home and getting up close and personal with the missus and daughters. The folks with a “complete absence of moral virtue” didn’t have the same ‘doctor knows best’ attitude, and did see a problem.3
Rodrigues Alves caught influenza during a pandemic, and died in 1919.
I’m not unsympathetic, but think working to convince doctors that washing their hands was a good idea would have been a better idea. (October 30, 2016)
The Anti-Vaccination Society of America got started after a visit by William Tebb. He was for social reform, against vaccination, concerned about premature burial, and paid for a drinking fountain in Burstow, England.
The fountain was dedicated to memory of the 400,000 horses killed and wounded during the Boer War. Tebb was also gung-ho about physical purity, food reform, and teetotalism. A colorful chap, in a colorful century. (April 9, 2017; November 11, 2016; July 10, 2016)
I said “colorful,” not praiseworthy.
That 1955 Keep America Committee flyer wasn’t, I think, mainstream.
But a decade later, I was running into folks who took such claims seriously. Some probably still do, with other vaccines on the ‘fear it’ list.
The third item of “the unoly three” was almost certainly a warning against the Alaska Mental Health Enabling Act.
Congress said the Act would improve mental health care in Alaska. Land allocated to a mental health trust would generate funds for the programs.
“…Mental Hygiene is a subtle and diabolical plan of the enemy to transform a free and intelligent people into a cringing horde of zombies….”
(Keep America Committee (May 16, 1955))
Zombies? Maybe they meant that metaphorically.
Other folks seemed equally convinced that the Alaska Mental Health Enabling Act was an international conspiracy masterminded by Jews, the Catholic Church, or psychiatrists.
Alaska’s legislature passed a law in 1978 that allowed selling the Alaska Trust land. I’m quite sure they weren’t thwarting an un-American plot.
They said the land would be more useful in the hands of municipalities, and individuals; or as forests, parks or wildlife areas.
A 1982 lawsuit led to a 1985 ruling that selling the land was illegal. A lot of different folks and outfits owned much of the land by then. The snarl got sorted out in 1994.
Some folks were still stirring the anti-Alaska Trust pot in 1992. Maybe that conspiracy theory will be revived, if the Alaska Trust gets into the news again.
Reasoned concerns about new medical technology, including vaccines, makes sense. The trick is sorting out facts and fears. (August 21, 2016)
“Drone vaccine delivery trial for island nation Vanuatu”
(June 14, 2017)
“Lifesaving vaccines in the island nation of Vanuatu will soon be delivered to remote areas by drone.
“A partnership between the government and the United Nations children’s fund (Unicef) will see a trial on drone medical delivery next year.
“The country is made up of a string of more than 80 islands – once known as the New Hebrides – many of which do not have airstrips or good roads.
“Most of the people live in rural areas and farm their own food.
“Vanuatu’s director general at the ministry of health said the test was a milestone for the small island nation….”
Getting vaccines to folks who need them makes sense. So does letting recipients know what the vaccines are for, and how to use them. Better yet, having someone with a little training on site to answer questions and at least supervise inoculations.
I’m pretty sure folks at UNICEF have thought of that.
This looks like a good idea. Part of a good idea, at least.4
These ‘drones’ are unmanned aerial vehicles, aircraft that fly without anyone aboard. Some are updated versions of model airships used in 19th century music hall acts and radio-controlled model airplanes flying at least since my younger days.
The last I heard, fully-autonomous drones are still in the research and development stage.
The fears would make sense, in a ‘good enough for a story’ way.
“Measles ‘tragedy’ kills 35 across Europe”
James Gallagher, BBC News (July 11, 2017)
“Thirty-five people have died in the past year from measles outbreaks across Europe, the World Health Organization has warned.
“It described the deaths – which can be prevented with vaccination – as an ‘unacceptable tragedy’.
“A six-year-old boy in Italy was the latest to die from the infection. More than 3,300 measles cases have been recorded in the country.
“The most fatalities – 31 – have been in Romania.
“But there have also been deaths in Germany and Portugal since June 2016….”
Rinderpest was an often-fatal disease for cattle, so dealing with that virus was a priority. It’s now one of two diseases we’ve managed to eradicate.
Most folks who catch measles recover, if they can rest and don’t develop any of several occasionally-fatal complications. But since a few folks will die after getting measles, we’ve developed MMR vaccine.
Result? A remarkable number of folks are scared of keeping their kids healthy. Not that they’d put it that way.
Bogus “scientific” research ranges from honest but stupid mistakes, through professional fraud, to crackpots and ethically-challenged journalists. Whatever the cause, it’s a bad idea. (April 28, 2017; December 16, 2016; August 26, 2016)
What’s sad is that the MMR vaccine works, and should be available anywhere in Europe. Those folks didn’t have to die.
“DR Congo polio outbreak ‘from poor vaccine coverage’”
(June 14, 2017)
“Two outbreaks of polio have been identified in the Democratic Republic of Congo, in a blow to the goal of wiping out the disease from the world.
“The World Health Organization said there was a high risk the vaccine-derived virus could spread.
The strain of polio involved comes from areas with poor vaccine coverage.
A similar outbreak, linked to low immunisation rates, was confirmed last week in Syria….”
Some RNA viruses, like the ones causing the common cold, are more of a nuisance than a threat. Others, like poliovirus and the measles virus, are occasionally lethal.
A little over a century after Landseiner and Popper’s work, we have comparatively safe and effective vaccines that can protect folks from the disease.
But like any other technology, the vaccines won’t work unless they’re used properly.
Some vaccines, including those used in the Democratic Republic of the Congo, use viruses that are weakened, but not dead. Inactivated vaccines, where the viruses are dead, are not necessarily safer.
An emotionally-convincing tale could still be spun about the evils of vaccine, based on experiments done in the mid 1930s.
Decades after two disastrous experiments, McCarthism enthusiasts included “polio monkey serums” in their “sign of the unholy three” marketing flier.
Their “polio monkey serums” probably depended on memories of Dr. Brodie’s experiments for emotional impact.
The New York University researcher had tried a dead-virus vaccine on himself and several thousand children.
They didn’t die, but many developed severe allergic reactions to the vaccine. They didn’t have immunity to polio, either.
Dr. Brodie’s career was essentially over. He died a few years later, in his late 30s. I don’t know why, although rumors of suicide are plausible.7
Dr. John Kolmer tested a weakened-virus vaccine on several thousand children, the same year as Brodie’s experiment. They didn’t acquire immunity. Several caught polio. Nine of them died.8
Happily, other researchers kept working. I talked about that earlier.
We’ve learned a great deal since 1935. My guess, and hope, is that Dr. Brodie thought his vaccine was safe for human testing. Using himself as a test subject certainly suggests that. The results were still tragic.
Vaccines used in the Democratic Republic of the Congo, DRC, weren’t experimental. The problems in that case were — complicated.
Folks in that photo, taken on the Congo River in 2008, were refugees. They were living on abandoned barges. The barges had once hauled agricultural and industrial products.
Polio outbreaks are just one of the problems folks in the DRC face.
Folks have lived there for — a very long time: 90,000 years, at least. My guess is that it’s a whole lot longer. ‘It happened earlier’ seems like a common theme in our growing knowledge of Earth’s past, and ours. (June 16, 2017)
Folks living in the Congo basin should be prospering. Their land has abundant mineral resources, good farmland, a nice climate, and the Congo River. The Congo is one of Earth’s major rivers.
That is in a hoped-for future.
Today, the territory is a mess.
The 2016 Human Development Index ranked the DRC’s level of human development at 176 out of 187.9 There are worse places to live, but not many.
“Congo” was arguably easier for Europeans to pronounce than the regional name, Nzadi O Nzere, River Swallowing Rivers.
“Mississippi” is what happened when Frenchmen tried saying Mshi-ziibi, “Big River.” And that’s another topic.
I won’t blame all of the Congo basin’s problems on Belgium. But Leopold II’s rapacious rule was a bad idea, and conditions haven’t been much better since.
From roughly 1390 to 1891, Kingdom of Kongo was a semi-independent nation, a sort of junior partner of Belgium.
Non-European slavers like Tippu Tip didn’t make life easier for folks living there. Neither did Portuguese merchants who were major clients of the slavers.
On top of that, the kingdom’s internal politics seem to have been rather intense.
In 1885 Belgium’s King King Leopold II told other European leaders that he’d be doing humanitarian and philanthropic work in Kingdom of Kongo. They apparently believed him, so until 1908, Leopold’s “Congo Free State” was the king’s personal property.
His notion of ‘uplifting’ folks living there was to relieve them of all the ivory, rubber, and minerals he could ship out. Even by the period’s standards, his conduct was appalling.
International pressure convinced Belgian’s government to rename Leopold’s Congo Free State as the Belgian Congo.
That lasted from 1908 to 1960. It wasn’t quite more of the same.
The territory has been independent since then, endured a succession of dubiously-ethical leaders, and has been renamed a few times. It is currently not the worst place on Earth to live. By a narrow margin.
Why should I pay attention to what’s happening there?
I’m interested in the science involved in sorting out the polio outbreak.
And I must not pretend that my neighbors are limited to folks I know personally. (Matthew 22:36–40, Mark 12:28–31; Matthew 5:43–44; Mark 12:28–31; Luke 10:25–30; Catechism of the Catholic Church, 1825)
I think the World Health Organization’s polio eradication efforts are a good idea. We’ve got a pretty good chance of succeeding, too.
Not “soon” by American standards, maybe. But we’re down to a few dozen known cases a year. My guess is that we’re no more than a few decades from putting polio on the “eradicated” list, along with smallpox and rinderpest. Or could be, if we keep working.
I also looked into how a vaccine-derived poliovirus happens.
Vaccines with weakened live viruses are safe and effective. That’s true only if enough folks in an area get immunized. Having creature comforts like water and sewage treatment tech helps.
Folks living in many, most, parts of the DRC don’t. Many didn’t get immunized.
Inadequate sewage treatment isn’t a problem by itself. Not where poliovirus is concerned. It’s still a good idea, for other reasons.
Where was I? polio, vaccines, sewage treatment. Right.
If everyone in an area is immunized, it won’t matter that kids get exposed to the attenuated poliovirus. The viruses will die if they don’t promptly reinfect another person. End of problem.
Even if an unimmunized kid gets infected with the weakened vaccine virus, the results are the same as if he or she took the vaccine normally.
The weakened virus will trigger an immune response, the kid acquires immunity, and the viruses die. When everyone’s immune, all viruses are dead. End of problem again.
However — viruses, including the one that causes polio, mutate and evolve rapidly.
With enough unimmunized folks around, a vaccine-derived virus strain will keep moving from host to host. There’s a chance that it’ll change into a fully active virus. Then we have a polio outbreak. Big problem.
Getting polio vaccines to folks is a good idea. So is making sure that enough folks get immunized. This is a job that, once started, should be finished.
St. Hildegard’s “Physica” and “Causae et Curae” helped lay foundations for the branch of philosophy we call science.
Nearly a millennium after St. Hildegard’s work, we’ve learned quite a bit. We’ve also acquired some very odd notions.
Some, not all, Christians act as if using the brains God gave us is sinful.
Some, again not all, scientists act as if they think a core value of Christianity is avoiding knowledge. Considering the antics of some Christians, I can understand their attitude: but don’t agree.
Some scientists, like Gregor Mendel, have been unequivocally Christian and Catholic.
Mendel’s experiments with peas and mice were much later recognized as groundbreaking genetics research. He was also an Augustinian friar and abbot, so his religious beliefs are fairly obvious.
Others, like Louis Pasteur, weren’t quite as blatantly Catholic.
In Pasteur’s case, I think some assumptions about his beliefs may come from his refusal to mix religion and science. Mendel didn’t either; but like I said, he was an Augustinian friar and abbot.
My culture’s recent history might make imagining someone rejecting either faith or science easy enough. Attempting a ‘scientific’ faith or ‘Biblical’ science is another option. But not, I think, a good option.
America’s ‘Bible thumper’ subculture was developing ‘creation science’ during my youth. Small wonder so many Americans assume that religion and reality don’t mix. (March 31, 2017)
My experience suggests that thumpers started losing their penchant for ersatz Elizabethan English around the time ‘creation science’ hatched.
Their ‘faith-based science’ details were new, but the basic ideas remind me of Hawkins’ imaginative effort to wrap new facts around his preferred reality:
“…Such is the Basis of Scripture, and such also is the legitimate deduction of History. But incontinent Liberality deceiving Faith, Reason, empty with the fumes of that same flattery by which we originally fell, cometh of the unhallowed embrace, and finding in the crust of the Earth certain animal Types….”
(“The Book of the Great Sea-Dragons, Ichthyosauri and Plesiosauri,” Thomas Hawkins, Thomas; p. 1 (1840))
Embarrassing as ‘creation science’ is, I don’t see it as a physically dangerous belief. Faith healing’s far end is another matter. It’s been quite a while since I’ve heard of someone dying because their religion was against medical treatment, so maybe it’s on the wane.
The idea that God has anger management issues, and smites folks with disease? I suspect that was more common in the 18th century than now.
“for a man to infect a family in the morning with smallpox and to pray to God in the evening against the disease is blasphemy; that the smallpox is a judgment of God on the sins of people, and that to avert it is but to provoke him more; that inoculation is an encroachment on the prerogatives of Jehovah, whose right it is to wound and smite.”
(Contemporary reaction to inoculation experiments by American physician Dr. Zabdiel Boylston, circa 1720)
“Smallpox is a visitation from God; but the cowpox is produced by presumptuous man; the former was what Heaven ordained, the latter is, perhaps, a daring violation our of holy religion.”
(A physician’s reaction to Dr. Edward Jenner’s experiments in developing a vaccine for smallpox, (1796) via Psychological Sciences, Vanderbilt University)
Repeating what I’ve said before, and probably will again, I take my faith seriously.
“The whole truth” means just that: all truth. Not just the bits and pieces I like, or what we learned before some arbitrary date.
Since God created everything, including this universe, science and religion should get along fine. The same goes for faith and reason. (Genesis 1:1; “Fides et Ratio;” “Gaudium et Spes,” 36; Catechism, 159)
Quite a few folks were talking about ‘miracles’ then, the futuristic kind.
“…’Miracles You’ll See in the Next Fifty Years’ pretty much summed up the attitude of the day. We weren’t just going to see advances or novelties; we were going to see miracles….”
(“Life in 2000 AD,” Tales of Future Past, David S. Zondy)
I can get nostalgic about the era’s silly ‘world of tomorrow’ enthusiasm.
I don’t think it made any more sense than today’s equally-silly pessimism. But imagining a future “where jetpacks were as common as galoshes,” as David S. Zondy put it, was fun.
The “Miracles You’ll See…” article in a 1950 Popular Mechanics magazine was, I think, overly-optimistic.
But folks who were my current age at the time, born in 1885, had reason to be enthusiastic about the next half-century. Particularly if they were like me, and remembered what living in ‘simpler times’ was really like.
The first cholera pandemic ran from 1817 to 1824. We don’t know how many died.
The second cholera pandemic, from 1829 to 1849, was probably just as bad.
Details of the fifth cholera pandemic are debatable. Debated, anyway. What’s more certain is that it lasted from 1881 to 1896, and killed a lot of folks. Again, we don’t know exactly how many.
The sixth and seventh cholera pandemics, 1899-1923 and 1961-75, were more of the same. We haven’t had another one since. Outbreaks and epidemics, yes. Pandemic, no. That’s progress. Stopping cholera is also part of a job we haven’t finished yet.
I’m not surprised that we don’t have exact numbers for how many folks died in those global disasters. Survivors of an epidemic or pandemic understandably focus more on burying bodies and rebuilding their society, less on compiling records.
Another priority would be healing folks who are still sick. Or, better yet, keeping folks from getting sick in the first place.
Folks from Europe to China had noticed that disease was more likely near fetid swamps and other smelly places. Common-sense prevention, like not touching sick people, wouldn’t keep you healthy.
The most obvious common factor was contact with foul-smelling air.
Miasma theory was the consensus scientific explanation for disease until about 130 years back. Other theories. like contingent contagionism, had been suggested. The contagionism-miasma debate was big among doctors in the 19th century.
The idea that disease was spread by tiny “seeds” was over two thousand years old, but ‘bad air’ seemed a more reasonable explanation. That, we could smell. And correlations between ‘night air’ and disease were well-documented. Causation seemed plausible.
Certainly more plausible than the idea that tiny little critters we can’t see are bad for us. That idea took a long time to catch on.
Agostino Bassi found a tiny fungus that made silkworms sick. In 1844, he said that maybe tiny organisms caused diseases in humans, too.
John Snow traced the 1854 Broad Street cholera outbreak to a specific well. Meanwhile, scientists in Italy ignored Filippo Pacini’s isolation of Vibrio cholerae, the cholera bacillus. Miasma theory was really popular.
Eventually, Louis Pasteur and Robert Koch produced evidence that couldn’t be ignored. My guess is that today’s germ theory of disease isn’t the whole story.
I keep saying this: we have a great deal left to learn.
Paul Ehrlich’s 1900 Zauberkugel, magic bullet, isn’t “magic.”
It’s his name for a then-hypothetical agent that could be ‘aimed’ at disease organisms. I think naming something makes thinking about it easier.
In this case, it arguably helped Paul Ehrlich — he’s not the famous author — study human immune systems and develop Salvarsan, the first effective treatment for syphilis.
That was in 1910.
We’d used antibiotics for millennia, along with other ‘folk medicine’ cures.
What made some ‘medical miracles’ of the 20th and 21st centuries, including eradication of smallpox and rinderpest, possible was learning how some folk remedies worked.
It’s not ‘magic,’ and antibiotics aren’t ‘miracles.’ All they did was make it possible, after millennia of suffering and death, to finally cure — and prevent — many diseases.
Folks living in the 1950s had reasons for their enthusiasm and optimism.
They had problems, too; some of them very serious. So do we. But we have cause for enthusiasm and optimism, too. Reasonable optimism:
- “‘The Federation of the World’”
(May 28, 2017)
- “Good Intentions”
(May 12, 2017)
- “Bogs and Bison”
(February 10, 2017)
- “Authority, Superstition, Progress”
(October 30, 2016)
- “Europa, Mars, and Someday the Stars”
(September 30, 2016)
- Centers for Disease Control and Prevention
- World Health Organization (Updated April 2017)
- Global Polio Eradication Initiative
- “Last steps in polio eradication prove challenging”
Stephanie Soucheray, CIDRAP – Center for Infectious Disease Research and Policy, University of Minnesota (September 27, 2016)
- “‘The crowd is crazy, the crowd is a woman’: the oligarchical-federal demophobia of the First Republic and the issue of transferring the capital”
Christian Edward Cyril Lynch; Instituto de Estudos Sociais e Políticos/Universidade do Estado do Rio de Janeiro (Received for publication July 2011; Approved for publication in March 2012) translated by Naomi Sutclife de Moraes
- “Brazil: Five Centuries of Change”
Chapter 5, The Vaccine Riots and the Difficulty of Modernization in Rio de Janeiro
Thomas E. Skidmore (2010)
- “Call for applications: Cargo delivery RPAS Challenge in the Pacific”
Drones – Vanuatu, Stories of Innovation, UNICEF
- “About Me and This Blog”
- “The Speckled Axe” (April 9, 2017)
- “Internet Friends, Real People” (March 19, 2017)
- “Sweet Potatoes, Genes, and Long Life” (October 21, 2016)
- “Elastic Brains and New Tech” (October 14, 2016)
- “Respecting Everyone” (June 18, 2017)
- Centers for Disease Control and Prevention
- National Institutes of Health
- “PVR poliovirus receptor [ Homo sapiens (human) ]”
NCBI, NIH (Updated August 13, 2016)
- “The Spatial Dynamics of Poliomyelitis in the United States: From Epidemic Emergence to Vaccine-Induced Retreat, 1910–1971”
Barry Trevelyan, Matthew Smallman-Raynor, Andrew D. Cliff; Annals of the Association of American Geographers; via NCBI (June 2005)
- “Transgenic mice expressing a human poliovirus receptor: a new model for poliomyelitis.”
Ren RB, Costantini F, Gorgacz EJ, Lee JJ, Racaniello VR; Cell; via PubMed (October 19, 1990)
- “PVR poliovirus receptor [ Homo sapiens (human) ]”
- “Understanding the recent polio outbreaks”
Ryan Hyland and Teresa Schmedding; Rotary [non-technical FAQ/backgrounder]
- “Notes from the Field: Circulating Vaccine-Derived Poliovirus Outbreaks — Five Countries, 2014–2015”
Michelle Morales, MD, Chimeremma D. Nnadi, MD, PhD, Rudolf H. Tangermann, MD, Steven G.F. Wassilak, MD; Morbidity and Mortality Weekly Report (MMWR); Centers for Disease Control (February 12, 2016)
- “Coxsackievirus in children: How serious is it?”
Jay L. Hoecker, M.D.; Patient Care & Health Info; Mayo Clinic (January 17, 2015)
- “Calibration of Multiple Poliovirus Molecular Clocks Covering an Extended Evolutionary Range”
Jaume Jorba, Ray Campagnoli, Lina De, Olen Kew; Journal of Virology; (May 2008) via US National Library of Medicine, National Institutes of Health Centers for Disease Control
- World Health Organization
- “Circulating vaccine-derived poliovirus type 2 – Democratic Republic of the Congo”
(June 13, 2017)
- “What is vaccine-derived polio?”
(Updated April 2017)
- “Circulating vaccine-derived poliovirus type 2 – Democratic Republic of the Congo”