Comparison: 2009 H1N1 Pandemic Versus 2020 Coronavirus Pandemic

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The CDC notes, “This differs greatly from typical seasonal influenza epidemics, during which about 70% to 90% of deaths are estimated to occur in people 65 years and older.”

The CDC also points out that although the 2009 flu pandemic mostly affected children and young and middle-aged adults, the global impact was less severe than earlier pandemics. For example, previous pandemic mortality rates (percentage of people who died from the disease globally) were:

• 2009 H1N1 pandemic — 0.001 to 0.007% of the world’s population

• 1968 H3N2 pandemic — 0.03% of the world’s population

• 1918 H1N1 pandemic — 1 to 3% of the world’s population

It’s early in the COVID-19 pandemic to really get an accurate sense of the fatality rate. One estimate by a group of infectious disease experts cites 1.4% in people who have symptoms. This is largely based on the city of Wuhan, China, where the pandemic originated. However, many experts believe that rate is high because it took a while for health authorities to understand what was happening. For example, epidemiologist Jeffrey Shaman of the Mailman School of Public Health at Columbia University conducted a study on Wuhan and projected that in the early stages of the disease, as few as 14% of people in Wuhan were detected.

“I think there are many more than the [nearly] 700,000” confirmed COVID-19 cases in Hubei province, he told reporters. And by that estimate, the actual fatality rate would likely be much lower. Earlier estimates were 2% to 3%, with higher rates of almost 4%. Seasonal flu is about 0.1%.

Another aspect of that is that outside of Wuhan, the death rate in China was about 0.7%, or less than 1 fatality per 100 cases. Also, as the first country to deal with COVID-19, China exemplified a problem that is still ongoing, but less so—they had to figure out how to best treat the disease. And by the time people were showing up in hospitals—and quickly overwhelming them—they already had severe disease.

Although it is not unusual in pandemics, over time, the fatality rate of COVID-19 has steadily decreased. For example, according to the China CDC study, in patients whose symptoms began between January 1, 2020 and January 10, 2020, the fatality rate was an astonishing 15.6%. But in the patients who didn’t report illness until February 1 to February 11, in China, it was 0.8%.

Still, STAT writes, “It’s worth noting that even after China got the death rate down to 0.7%, or even 0.4%, that’s still about four to seven times greater than the death rate for seasonal flu. (The rate for the flu is about 0.1%—or 1 in 1,000 patients.)”

Of concern is how hard Italy is being hit, with 31,506 confirmed cases and 2,503 deaths. South Korea implemented sweeping and rapid testing and government response and has 8,320 confirmed cases, but only 81 deaths. Two theories for why Italy is being hit so hard hinge on two things: it has the second-oldest population on the planet, and its younger population tends to mingle more often with the elderly. A full 23% of the population is older than 65, compared to the U.S., for example, where it is 16%. In South Korea, it’s 18.5% of the population that is 60 years or older. And data from Italy indicates that 90% of the deaths are in people 70 years of age or older. What further complicates matters is that in South Korea, most of the diagnosed cases are in younger people, with only 20% in people 60 years old or older. About 30% are people in their 20s.

There has also been speculation that, as in China, there were a number of undiagnosed cases in Italy that created multiple lines of contagion. The Italian health authorities have already noted that they had a higher than usual percentage of pneumonia hospitalizations before recognizing the outbreak.

Another aspect of the 2009 H1N1 pandemic is the U.S. government’s response. In the early days of the H1N1 2009 pandemic, the number of cases is remarkably similar to what has been seen in the U.S. so far with the coronavirus. As The Washington Post writes, “We know that the number of H1N1 infections was actually much higher than what’s shown on each day, in part because epidemiologists later went back and created the estimates that Trump now uses for his comparisons. But we also—again—know that the number of coronavirus cases is much higher, too. We don’t know how much higher, in part because of the slow rollout of testing by the government.”

Generally, experts lauded the Obama administration on its response to the 2009 H1N1 epidemic. Although the current administration is taking some hits on poor response for testing and active denial on the part of the Trump administration as to the seriousness of the outbreak, state and regional governments have begun taking definitive action, shutting down bars and restaurants and placing limits on public gatherings in an effort to “flatten the curve,” which refers to spreading out the number of infections so healthcare institutions won’t become overwhelmed—as they did in China and Italy.

Hopefully the efforts will be effective. Epidemiologists believe COVID-19 will likely affect millions of people in the U.S., and if social distancing and early efforts for prevention are not effective in flattening the curve, the fatality rate could exceed that of the 2009 H1N1 pandemic as doctors and hospitals are overwhelmed by the number of cases.