Swine Flu Vs. COVID-19: Here's How the Two Pandemics Compare, According to Experts
Swine flu and COVID-19 have been repeatedly compared in the past few months, given that they're both pandemics that sparked major panic across the world and in the US. But while these two illnesses have some things in common—symptoms, diagnoses—they're actually quite different on many, many levels.
"Swine flu was the last major pandemic we had before COVID-19," Amesh A. Adalja, MD, senior scholar at the Johns Hopkins Center for Health Security, tells Health. "But they're not the same. COVID-19 is definitely more serious."
Richard Watkins, MD, an infectious disease physician in Akron, Ohio, and a professor of internal medicine at the Northeast Ohio Medical University, agrees. "COVID-19 can lead to organ damage and long-term symptoms," he tells Health. "That isn't seen with swine flu."
Given that the swine flu pandemic happened back in 2009, you might be a little fuzzy on what went down and why it was such a big deal. Here's what you need to know, why officials are comparing responses now, and how it measures up to COVID-19.
Real quick: What is swine flu, again?
Swine flu was a novel influenza A (H1N1) virus that emerged in the spring of 2009, according to the Centers for Disease Control and Prevention. COVID-19, on the other hand, was a novel coronavirus—so swine flu and COVID-19 are two different types of viruses.
Swine flu was detected first in the US and then spread across the country and eventually the world, and it contained a blend of flu genes that hadn't been previously seen in animals or people, the CDC says. "It was a new virus that jumped from pigs to humans," Dr. Adalja says. (Similarly, COVID-19 is also a zoonotic disease—which means it jumped from animals to humans—though there's no clear path as of right now.)
But now, swine flu is just another seasonal influenza strain, Dr. Adalja says. That means it comes back every year (don't worry, our flu vaccine has taken that into account, but more on that later). "The H1N1 2009 influenza strain still circulates every flu season," Michelle DallaPiazza, MD, associate professor at the Rutgers New Jersey Medical School, tells Health.
How many people were infected with—and died from—swine flu compared to COVID-19?
From April 12, 2009 until April 10, 2010, the CDC estimates that up to 60.8 million people were infected with swine flu. That flu led to an estimated 274,304 hospitalizations, and, according to estimates, 12,469 deaths over the course of that year.
That death count is in huge contrast to the current coronavirus pandemic. Infections of COVID-19 in the US are still increasing, but the latest data from the Johns Hopkins University Coronavirus Resource Center shows that 7.5 million people in the U.S. have been infected with the virus to date. More than 212,000 Americans have currently died of COVID-19, Johns Hopkins reports.
But comparing COVID-19 cases to swine flu cases is difficult, Thomas Russo, M.D., professor and chief of infectious disease at the University at Buffalo, tells Health. "With COVID-19, we're counting documented cases," he says. "With influenza, they're CDC estimates. They assume—which is true—that not all influenza cases will be documented." Therefore, it's not necessarily comparing apples to apples, Dr. Russo says.
Overall though, "the impact of the COVID-19 pandemic has been much more devastating," Dr. DallaPiazza says. "Some of the reasons for that include, we have no existing treatment or prophylaxis for COVID-19 like we did for H1N1 2009, People over 65 most likely had some natural immunity to other H1N1 influenza viruses they had been exposed to many years prior, and most importantly, COVID-19 has a higher infection rate and a higher case-fatality rate."
How do the symptoms of swine flu compare to COVID-19?
The symptoms of swine flu in people are similar to symptoms of other strains of the flu, according to the CDC. Those include:
- Sore throat
- Body aches
In some cases, people with swine flu also experienced vomiting and diarrhea.
There's a range of symptoms that come with COVID-19, but the CDC says these are the most common:
- Fever or chills
- Shortness of breath or difficulty breathing
- Muscle or body aches
- New loss of taste or smell
- Sore throat
- Congestion or runny nose
- Nausea or vomiting
How are swine flu and COVID-19 diagnosed?
Given that both viruses can have similar symptoms, it's difficult for doctors to tell them apart without doing a test, Dr. Adalja says. Both are diagnosed in a similar way, though. The CDC says that the following ways of testing for COVID-19 are considered acceptable:
- A nasopharyngeal swab (which goes up the nose and is the preferred method of testing)
- An oropharyngeal swab (which goes into the back of the throat)
- A nasal mid-turbinate swab (which doesn't go in as far as a nasopharyngeal swab)
- An anterior nasal swab (which just collects a specimen from the nostril)
- A nasopharyngeal wash (which uses saline solution to collect a sample)
Swine flu is diagnosed the same way as other forms of the flu, Dr. Adalja says. Per Medline Plus, that includes:
- A nasopharyngeal swab
- An oropharyngeal swab
- A nasopharyngeal wash
Does swine flu or COVID-19 have any approved vaccines or treatments?
Again, swine flu is just one strain that's part of the annual flu now, so it's treated as such, Dr. Adalja says. That means the flu vaccine is thought to help protect against getting the virus or, at least, from developing serious complications of swine flu. Swine flu can also be treated with anti-viral medications. Those include the following, per the Food and Drug Administration (FDA):
- oseltamivir phosphate (Tamiflu)
- zanamivir (Relenza)
- peramivir (Rapivab)
- baloxavir marboxil (Xofluza)
"When swine flu emerged, there was at least some population immunity in certain people that protected them against having severe disease from the strain when it emerged," Dr. Adalja says. "We had a very well-ironed vaccine development process and antivirals."
As of now, however, there is no approved treatment or vaccine for COVID-19. Many hospitalized patients are treated with the steroid dexamethasone and anti-viral remdesivir, Dr. Watkins says. But again, these aren't approved treatments. "For the novel coronavirus, we have no vaccine, no anti-virals, no population immunity," Dr. Adalja adds.
What was the US response to swine flu compared to COVID-19?
This has come up a lot in politics. Barack Obama was in office during the swine flu pandemic and Dr. Adalja says the Obama administration "could have done better with guidance and how things unfolded in terms of personal protective equipment needs, the vaccine development process, and the delivery process."
"There were some mistakes, but it wasn't anything too consequential," Dr. Adalja says, adding that, "once public health officials realized that swine flu wasn't going to be cataclysmic, they backed down on mitigation efforts like school closures and social distancing."
But, Dr. Adalja says it's very difficult to compare the Obama administration's swine flu response to that of the Trump administration's handling of COVID-19. "Whatever faults the Obama administration had with their response to the 2009 pandemic, those are dwarfed by continual errors from the Trump administration that are continuing to this day," he says. Those include, but aren't limited to: failing to take the deadly illness seriously, slashing funding for critical public safety nets, and significantly lagging in testing during the first weeks and months of the pandemic.
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