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Challenge 2: Hospitalization Rates for the Seasonal Flu v. COVID-19

Learning Targets:

  • Differentiate between a pandemic and epidemic.
  • Analyze and interpret epidemiological data.
  • Perform calculations in order to accurately compare data.
  • Identify and use credible sources to find data to support a conclusion.


Coronavirus is not like the flu. It’s much worse.

The story continues...

One afternoon, June and her siblings, her brother Ruben and older sister Carla, are sitting around the family room of their home with the TV tuned in to a local channel. A preview for the evening news comes on and the newcaster asks in a serious, but dramatic voice, “Hospitalization rates for COVID-19 are on the rise, could the number of hospitalizations outnumber those for last year’s seasonal flu?”

“Wait a minute,” Ruben says, “I thought this pandemic is more serious than the seasonal flu. I didn’t realize that people are hospitalized with the flu so often.”

“Yeah,” June agrees, “I know lots of people who have had the flu and they miss a few days of school, but then they are fine.”

“Well, just like we are seeing with COVID-19, some people are more vulnerable than others and end up with more serious medical conditions from the flu,” Carla describes inserting her knowledge of public health.

“My friend Ray has a cousin who is a nurse at the hospital in New Haven and apparently, there have been a ton of hospitalizations for COVID-19 in the last few months and at times it’s been overwhelming,” June says.

“Yeah, it doesn’t seem like the seasonal flu overwhelms hospitals the way that COVID-19 has,” Ruben comments.

Investigate & Analyze

Part 1. Comparing hospitalizations from the seasonal flu and COVID-19

“Let’s look at the data and see what the numbers say,” Carla suggests. And she pulls up a few sources of data, two are compiled by the Centers of Disease Control and one by the NYTimes.

Seasonal Flu 2018-19 CDC:
US Coronavirus data NYTimes:
*Why are we using the data for the 2018-19 season of influenza? This is the most recent data set finalized by the CDC, which means the numbers are set. Also, the COVID pandemic has impacted the last few flu seasons due to social distancing and mask wearing.

image: pandemic “June, why don’t you look up the number of hospitalizations for last year’s seasonal flu, and Ruben, you can look at the number of hospitalizations for COVID-19 thus far,” Carla directs them to the websites.

Use the websites to answer each question below about hospitalizations for the 2018-19 season of influenza and for COVID-19.

  • Conclude:
    • Which age group had the largest number of hospitalizations due to influenza in the 2018-19 season?
  • Calculate and Conclude:
    • Which age group had the largest hospitalization rate (per 100,000) during the entire 2018-19 flu season?
  • Reflect and Discuss:
    • If your answers to the above two questions are different, explain what could account for this difference.
  • Investigate:
    • What was the percentage of patients hospitalized with COVID-19 for the week ending 09-Jan-2021 (the week with the greatest number of hospitalizations in the pandemic so far) who were 65+? How about the percentage of people who were 0-4?
  • Compare:
    • How do the percentages you found in part d compare to the percentages of people in the same age groups hospitalized with the seasonal flu in 2018-19?
  • Discover:
    • Using the NYTimes coronavirus data, find the chart under “US Trends” that illustrates the all time number of hospitalizations during the pandemic. Use this chart to find 7-day average hospitalizations on Jan. 9, 2020.
  • Compare:
    • Compare the number you identified in part f to the total number of hospitalizations for the entire flu season of 2018-19.

Part 2 - Hospitalizations before and after wide-spread vaccination

Carla reflects on this flu comparison and then on how the landscape of the pandemic has changed, “unlike in the winter of 2020-21, we now have several vaccines for COVID-19 that are effective at preventing severe COVID-19. This surely has impacted hospitalization rates.”

“Are you sure? It seems like there are still a lot of COVID-19 cases these days,” Reuben says.

“Well, let’s look at what the data says,” Carla replies as she pulls up yet another CDC website with hospitalization data.

CDC Hospitalization Data:

Use this website to answer each question below about hospitalizations for COVID-19 before and after wide-spread vaccination.
  • Investigate:
    • Using the graphic to search by jurisdiction, find current 7-day average for new hospital admissions for the week of Dec. 31, 2020 to Jan. 6, 2021 for the following jurisdictions:
      • United States
      • Connecticut
      • Mississippi
  • Compare:
    • Again using the graphic, find current 7-day average for new hospital admissions for the week of Aug. 18, 2020 to Aug. 24, 2021 for the following jurisdictions:
      • United States
      • Connecticut
      • Mississippi
By October of 2021, according to the NYTimes, about 70% of residents of Connecticut had been fully vaccinated compared to 44% of residents in Mississippi.

Reflect & Discuss



  • Do the seasonal flu and COVID-19 seem to affect population groups similarly?

Are all ages affected equally?

  • Do you think the seasonal flu or COVID-19 is a bigger burden on hospitals?
Estimate the number of hospitalizations due to COVID-19 over a month, several months, or year.
  • What preventative measures are in place for the seasonal flu that impact hospitalization rates?

How is the flu prevented? Also, are there treatments that exist for the flu?

  • Did hospitalization numbers change between January and August of 2021?
Where did they decrease or increase?
  • Does the data on hospitalizations support the idea that vaccinations prevent severe COVID?
Factor in the vaccination rates when comparing hospitalizations in different jurisdictions.