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Five myths about outbreaks

No, closing borders can’t stop the spread of disease.

A health care worker checks arriving passengers at the Monrovia airport in Liberia in 2014, at the height of the Ebola epidemic. (Michel du Cille)

One hundred years ago, Pvt. Albert Mitchell, an Army mess cook stationed at Fort Riley, Kan., received the first diagnosis of a new strain of influenza that eventually infected approximately 500 million people across the globe — about one-third of the world’s population — and led to at least 50 million deaths, far more than the lives lost in the still-raging World War I . The Spanish flu pandemic brought new urgency to the quest to comprehend infectious diseases and the way they work, but the subject is still beset by scientific challenges and popular misunderstandings. Here are five of the most tenacious.

Myth No. 1

A pandemic on the scale of Spanish flu is unlikely today.

After the outbreak of H1N1 — or swine flu — in 2009, the World Health Organization (WHO) warned that “the world is now at the start of the 2009 influenza pandemic.” Many researchers questioned that finding, with Philip Alcabes announcing in these pages that “we’ll never see another flu outbreak” like the Spanish flu. Some said the WHO was unnecessarily raising anxieties; others suggested that the agency had been unduly influenced by the pharmaceutical industry, which would stand to make money in preparing for and treating an outbreak. A headline in Frontiers in Public Health held that medical advances have made it “Unlikely That Influenza Viruses Will Cause a Pandemic Again Like What Happened in 1918 and 1919.”

And it’s true that we’re much better than we were a century ago at detection and containment, we have antiviral drugs that save the lives of some infected patients, and the 575,000 lives that swine flu took were a small fraction of the Spanish flu total.

But most global health experts agree that it’s only a matter of time before a combination of risk factors makes us vulnerable to another pandemic. We may even be overdue. Unlike in 1918, a disease can cross the globe in a fraction of the time it takes to show symptoms and before health officials realize that a crisis is brewing. And increasing urbanization worldwide, alongside weak health systems, means vulnerable people are living on top of one another. That’s the tinder epidemics need to explode.

Myth No. 2

Most adults don't need the annual seasonal flu vaccine.

In the United States, just over 40 percent of adults get the seasonal flu vaccine; the number is higher for children but still less than 60 percent. In a 2015 Truven Health Analytics-NPR Health Poll, 38 percent of Americans said they planned to skip the flu vaccine: 48 percent of those said they didn’t need it, and 30 percent worried about the risks, including a concern that the shot might give them the flu. And it’s true that, in a good year, the vaccine is about 60 percent effective; the efficacy of this year’s cocktail has ranged as low as 25 percent for some strains, making this winter one of the worst flu seasons in years.

Still, the seasonal flu vaccine remains the best way to prevent infections. For millions, it can stave off serious complications and even death. Since 2010, influenza has resulted in up to 60.8 million illnesses, 710,000 hospitalizations and 56,000 deaths per year in the United States, according to the CDC. The seasonal flu vaccine also creates herd immunity, stopping the disease’s spread when a critical mass of people get vaccinated. Some protection is far better than none.

Ideally, as Anthony Fauci of the National Institutes of Health and other researchers have recently argued, we’d replace the annual seasonal flu vaccine with a more effective universal one that would cost much more to develop but result in permanent immunity. Unfortunately, manufacturers, which benefit from the current $3.3 billion seasonal flu vaccine market, have little incentive to invest in a universal vaccine that would protect against all forms of influenza. Several members of Congress recently proposed $1 billion to fund research for this.

Myth No. 3

Some of the deadliest pathogens don't pose an imminent threat.

It’s easy to think that measles is no longer a threat, since the CDC declared that it had been eliminated from the United States in 2000. Bob Sears, a board-certified pediatrician in California and a well-known vaccine skeptic, says, “The risk of fatality [from measles] here isn’t zero, but it’s as close to zero as you can get without actually being zero.”

But between the CDC declaration and 2014, the annual number of reported measles cases in the United States ranged from 37 to 667. In this country alone, about 1 in every 20 children with measles gets pneumonia, 1 of every 1,000 gets encephalitis, and 1 or 2 out of 1,000 will die. Unless we’ve eliminated measles — and, for that matter, other infectious diseases such as polio and diphtheria — everywhere in the world, Americans will remain susceptible to them. Viruses travel.

Another error some epidemiologists make is to focus on the near crisis at the expense of the far one. In 2014, when the Ebola epidemic raged in Africa, pundits called it the “ISIS of biological agents,” President Obama sent troops to Africa, and Congress held hearings. Yes, Ebola is an incurable, often-lethal malady with no licensed vaccine, but it’s hard to transmit from person to person and an unlikely candidate for a pandemic. It is a mistake to treat it with so much urgency that we fail to neutralize other potential threats. Today’s vaccines prevent fewer than 30 human pathogens. But since 1940, researchers have identified more than 340 new diseases, and the number of annual outbreaks globally has increased from fewer than 800 in 1980 to more than 3,000 by 2010. The WHO warns that several emerging pathogens with few or no medical countermeasures may cause havoc in the near future, including such nasty ones as Crimean-Congo hemorrhagic fever, Ebola, Marburg virus disease, Lassa fever, MERS and SARS coronavirus diseases, Nipah, and Rift Valley fever. That doesn’t include other potentially epidemic diseases such as HIV/AIDS, tuberculosis, malaria, avian influenza and dengue fever, which already have major disease-control efforts but still would benefit from effective vaccines.

Myth No. 4

We need bigger vaccine stockpiles to halt outbreaks.

When yellow fever appeared in Angola and spread to Congo in 2016, the global yellow fever vaccine stockpile was not nearly big enough to give everyone there a full dose. Many have called for expanding the size of that stockpile, and it is a common subject of debate for a range of infectious diseases.

But logistical and economic challenges limit the size of any vaccine stockpile. It’s a complex business to get it just right. Egg-based vaccines, for example, are hard to scale up quickly; vaccines have a shelf life; and producing large quantities of vaccines that may never be used can be expensive and can take scarce resources away from routine immunization. Rather than focus too much on stockpiles, government and nongovernmental organization money would be better spent helping struggling countries immunize their populations to prevent infection. They should also build health systems capable of detecting and responding to outbreaks before they spread further — the objective of a valuable CDC global health initiative that’s now in danger of substantial downsizing.

Myth No. 5

Closing our borders will keep the nastiest bugs out.

At the height of the Ebola outbreak in 2014, a number of American public figures urged closing U.S. borders to travelers from the hardest-hit West African countries. “The bigger problem with Ebola is all of the people coming into the U.S. from West Africa who may be infected with the disease. STOP FLIGHTS!” tweeted Donald Trump, then a private citizen. At least 85 members of Congress agreed, the Hill reported.

Such responses rarely work; pathogens don’t respect borders. Efforts by countries to ban flights from nations with H1N1 outbreaks in 2009, for example, were ineffective, according to a 2011 study in the journal PLOS One. Also, cutting off contact with outbreak-affected countries can compound the problem by grounding supplies and personnel they need to fight the spreading disease. Most countries already take precautions to ensure that potential pathogens don’t cross borders: They require travelers to show immunization records or report symptoms, and subject them to thermal temperature scans at ports of entry.

Still, there’s no real substitute for preventing outbreaks at their source, through routine immunization, improved surveillance and other proven public health measures.

Twitter: @GaviSeth

Five myths is a weekly feature challenging everything you think you know. You can check out previous myths, read more from Outlook or follow our updates on Facebook and Twitter.