Scientists research whether Russian flu in the 19th century was caused by coronavirus

In May 1889, people living in Bukhara, a city that was part of the Russian Empire, began to get sick and die. The respiratory virus that killed them became known as the Russian flu. It swept the world, overwhelming hospitals and killing the elderly with ferocity.

Schools and factories were forced to close as many students and workers fell ill.

Some of those infected described a strange symptom: loss of smell and taste. And some of those who recovered reported persistent exhaustion.

The Russian flu finally ended a few years later, after at least three waves of infection.

Its patterns of infection and symptoms have led some virus experts and medical historians to wonder: Could the Russian flu really have been a pandemic caused by a coronavirus? And could its course give us clues about how the Covid pandemic will unfold and end?

If a coronavirus caused the Russian flu, some believe the pathogen could still be out there, its descendants circulating the world as one of four coronaviruses that cause the common cold.

In this case, it would be different from flu pandemics, where the viruses remain for some time and are replaced by new variants years later, which cause a new pandemic.

If that’s what happened with the Russian flu, it bodes well for the future. But there is another scenario. If today’s coronavirus behaves more like the flu, immunity against respiratory viruses is fleeting. This could mean a future of annual Covid vaccines.

But some historians express caution about the Russian flu hypothesis.

“There is very little, almost no hard data” about the flu pandemic in Russia, said Frank Snowden of Yale University.

There is, however, a way to solve the Russian flu mystery. Molecular biologists now have tools to extract ancient virus fragments from preserved lung tissue from Russian flu victims and find out what type of virus it was.

Some researchers are now looking for these tissues in museums and medical schools that may have ancient vials of specimens floating in preservative liquid that still contain lung fragments.

Russian flu

Virginia Tech University’s Tom Ewing, one of the few historians who has studied the Russian flu, has noticed striking parallels with the current coronavirus pandemic: institutions and workplaces closed because too many people were sick; doctors overloaded with patients; and waves of infection.

“I would say maybe,” Ewing said, when asked if the Russian flu was a coronavirus.

Dr Scott Podolsky, professor of global health and social medicine at Harvard Medical School, called the idea “plausible.”

And Dr. Arnold Monto, professor of public health, epidemiology and global health at the University of Michigan, called it “a very interesting speculation.”

“We have long wondered where the coronaviruses came from,” Monto said. “Has there ever been a coronavirus pandemic in the past?”

Harald Bruessow, a retired Swiss microbiologist and editor of the journal Microbial Biotechnology, points to an article published in 2005 that concluded that another coronavirus in circulation today, known as OC43, which causes severe colds, may have jumped from oxen to humans in 1890.

Three other less virulent coronaviruses are also circulating. Perhaps one such virus, OC43, is a remnant variant of the Russian flu pandemic.

While acknowledging the uncertainties, Bruessow would bet that the Russian flu was caused by a coronavirus. His work, which involved searching old newspapers, magazines and public health reports on the Russian flu, found that some patients complained of conditions such as loss of taste and smell and prolonged Covid-like symptoms.

Some historians have speculated that the “mal du siècle” in the 19th century may have actually been lassitude caused by the aftermath of the Russian flu.

These symptoms are not typical of flu pandemics.

Like Covid, reports Bruessow, the Russian flu appears to have preferentially killed the elderly, but not children. Ewing, examining 1890 records from the State Board of Health in Connecticut, found a similar pattern. If true, this would make the 1890 virus different from flu viruses, which kill both the very young and the very old.

For those looking for clues as to how the current coronavirus pandemic could end, some think the last two pandemics may offer a clue.

As the Russian flu pandemic subsided, said J. Alexander Navarro, a historian at the University of Michigan, “people quickly got on with their lives.” It was the same with the 1918 flu pandemic. Newspaper reports about it dwindled. And, he said, “mourning was almost entirely a private affair.”

“I highly suspect the same will happen today,” Navarro said.

“Actually, in many ways, I think it already does.”

When pandemics run out

Some pandemics — at least in the last hundred years, when their causes could be identified — were caused by respiratory viruses. Recent exceptions are zika and chikungunya — ancient mosquito-borne viruses — and HIV, which is transmitted through sexual intercourse and needle sharing.

Great plagues terrified humanity in ancient and pre-modern times, most notably the bubonic plague. Propagated mainly by rat fleas, it inaugurated a terrible period, killing multitudes in Europe from 1347 to 1352. There were so many dead that they buried them in mass graves, piled up.

The bubonic plague kept returning to Europe for centuries after it broke out. But how this plague ended offers few lessons relevant to today’s pandemic.

The researchers also failed to find answers in animal studies. They have been trying for decades to find general laws to predict how pandemics progress, infecting hundreds of thousands of mice with various viruses and bacteria, said Dr. George Davey Smith, professor of clinical epidemiology at the Bristol School of Medicine in England. The experiments continued year after year in England, Germany, the United States and Australia. Everyone looked for ways to predict when and how an epidemic might end.

Nothing was found.

“They couldn’t predict what was going to happen,” Davey Smith said.

Therefore, researchers trying to understand how respiratory pandemics end can only study the flu and the current coronavirus pandemic.

Only the flu pandemics ended. This, said Dr. David Morens, an influenza researcher and senior adviser to the director of the US National Institute of Allergy and Infectious Diseases, is a real limitation when trying to understand the natural history of respiratory disease pandemics.
“We only have 104 years and four different pandemics to make predictions,” he said.

Influenza pandemics are also perplexing.

The first of the four flu pandemics in which the virus is known began in 1918. The pandemic subsided after three waves of infections, and this virus, the H1N1, remained in circulation, in a less virulent form, until 1957, when it disappeared.

“As far as we could tell in 1957, this virus was gone forever,” Morens said.

Then came H2N2. It was substantially different from H1N1 and caused a pandemic. This pattern repeated itself with the emergence of H3N2 in 1968.

But in 1977 something strange happened. H1N1 is back after two decades gone. It and another virus, H3N2, have been circulating ever since.

“Until 1977, we never had two subtypes circulating at the same time,” Monto said. “We don’t understand why one subtype drove out the other and why it didn’t happen in 1977.”

And in 2009 the H1N1, which had reentered the human population in 1977, was replaced by a genetically distinct version that came from pigs, causing another pandemic.

But why would a new variant make the old one disappear?

That “is another mystery,” Morens said.

At least there are useful flu vaccines. But they have to be given every year because of declining immunity. In a study in England of common cold coronaviruses, researchers found that immunity to infections from these viruses also declines within a year.

“Will we need a Covid vaccine every year?” asked Dr. Jeffery Taubenberger, head of the section on viral pathogenesis and evolution at the National Institute of Allergy and Infectious Diseases. “That’s the direction we’re going.”

Then there is the question of why the Russian flu and now the Covid pandemic have produced waves of rising and falling mortality.

“We’re pretty ignorant, and that extends to the waves we’ve been seeing over the last couple of years with Covid,” Morens said. The evolution of viruses is not the complete answer, she added.

“There are no good explanations that I know of.”

^{Translated by Luiz Roberto M. Gonçalves}