One of our readers suggested that I review the book The Great Influenza: The Epic Story of the Deadliest Plague in History, by John M. Barry. It’s not a new book (it was published in 2004) but it is very pertinent to several of the issues that we have been discussing on this blog, especially in regards to the current anti-vaccine movement. It’s well worth reading for its historical insights, for its illumination of the scientific method, and for its accurate reporting of what science has learned about influenza.

In the great flu epidemic of 1918, influenza killed as many people in 24 weeks as AIDS has killed in 24 years. It’s hard to even imagine what that must have been like, but this book helps us imagine it. It tells horror stories: children found alone and starving beside the corpses of their parents in homes where all the adults had died, decomposing bodies piling up because there was no one left who was healthy enough to bury them. Sometimes the disease developed with stunning rapidity: during one 3 mile streetcar trip, the conductor, 3 passengers, and the driver died. In another incident, apparently healthy soldiers were being transferred to a new post by train; during the trip, men started coughing, bleeding, and collapsing; and by the time it arrived at its destination, 25% of the soldiers were so sick they had to be taken directly from train to hospital. 2/3 of them were eventually hospitalized in all, and 10% of them died. The mind boggles.

The 1918 epidemic was exacerbated by politics and military considerations. Because of WWI, young men were gathered and crowded into barracks and troops were transferred to new locations, helping the disease to spread. Quarantine recommendations were rejected because they might cause panic and interfere with the war effort. Vital public health information was censored to maintain morale, so the public (and many officials) were slow to realize the extent of the problem. Falsely reassuring bulletins were issued with unhelpful advice to prevent contagion by keeping warm, keeping the feet dry, and keeping the bowels open. It was named the Spanish flu not because it originated in Spain (the author thinks it most likely originated in Kansas) but because the Spanish government was the only one that allowed the truth to be publicized.

The book explains how the flu virus works, how it mutates even during a given flu season, what antigen drift and antigen shift are, why we have to keep changing the vaccines, and how antigen shift can result in an epidemic. It explains that the killer is not the virus but the body’s massive immune response. This is why young healthy people were most susceptible: their bodies were more capable of mounting a response to the virus. Understanding this would make people less susceptible to claims that a given alternative medicine “boosts the immune system.”

Ironically, the massive immune response itself damaged the lungs so that they were susceptible to bacterial invasion. Just as some patients were recovering from the influenza virus, they developed a bacterial pneumonia and died of complications. This muddied the waters and interfered with efforts to pin down the cause of influenza. For a long time, scientists thought it was caused by B. influenzae bacteria (now known as Hemophilus influenzae) because they were often able to culture this and other pneumonia-causing bacteria from flu victims. Some laboratories found the bacteria in virtually every patient, and when other labs failed to find it their results were dismissed as due to poor technique or critics said that if the bacteria could not be found, those patients must not have had the flu.

At that point in history, there was no way to detect a virus other than to demonstrate its presence indirectly by showing that the property of infectiousness could survive filtration that removed larger elements like bacteria. The story of how scientists searched for the cause of influenza is an illuminating one, full of set-backs and mistakes. It illustrates how science progresses step by step and how errors are eventually corrected.

Desperate patients were willing to try any proposed remedy. Some opened windows while others closed them; some hung camphor and garlic around their necks. Desperate doctors tried everything from rubbing creosote into the axilla to stimulating the heart with strychnine and digitalis. Homeopaths claimed a death rate of zero, but

…the results were self-reported, making it far too easy to rationalize away those under their care who did die – to remove, for instance, from their sample any patient who, against their advice, took aspirin which homeopaths considered a poison.

The epidemic ran its course and eventually subsided, mainly because of two factors: the population developed a degree of immunity, and the virus itself became less virulent due to reversion to the mean in the mutating viral population.

This book was written before the 2009 H1N1 pandemic, so it offers a step back into a time machine. It explains the thinking that would go into the 2009 response. Critics can second-guess authorities now that the 2009 H1N1 strain has turned out not to be as serious as feared, but this book makes it clear that influenza has devastating potential and that a strong response was fully justified in 2009 and will be justified again next time. And there will be a next time. I wish anyone who questions flu vaccines or who thinks influenza is not serious because it’s “just the flu” would read this book.

Posted by Harriet Hall

Harriet Hall, MD also known as The SkepDoc, is a retired family physician who writes about pseudoscience and questionable medical practices. She received her BA and MD from the University of Washington, did her internship in the Air Force (the second female ever to do so),  and was the first female graduate of the Air Force family practice residency at Eglin Air Force Base. During a long career as an Air Force physician, she held various positions from flight surgeon to DBMS (Director of Base Medical Services) and did everything from delivering babies to taking the controls of a B-52. She retired with the rank of Colonel.  In 2008 she published her memoirs, Women Aren't Supposed to Fly.