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FluHubWeek ending Sep 26, 2026

Historical data, 2010–11 to 2025–26

Flu seasons compared

How this season measures up against every season since 2010: outpatient illness, hospitalizations, deaths, vaccine effectiveness, and vaccination rates. Every number links to its CDC source.

Season scorecard

One row per season. Select a heading to sort; for example, sort by hospitalization rate to rank severity.

SeasonPeak %ILIPeak week endingHosp. rate per 100kEst. illnessesEst. hospitalizationsEst. deathsChild deathsVaccine effectivenessAdults vaccinatedChildren vaccinated
2025–268.3%Dec 2786.932M390K24K19536%––
2024–257.8%Feb 8127.251M710K45K29756%41.9%50.2%
2023–246.8%Dec 3079.637M430K26K21044%–55.4%
2022–237.4%Nov 2662.329M340K25K18730%46.9%57.4%
2021–224.9%Jan 113.311M120K6K4936%49.4%57.8%
2020–212.3%Sep 4––––1–50.2%58.6%
2019–207.1%Dec 2865.934M380K26K19939%48.4%63.7%
2018–195.0%Feb 1663.529M400K32K14529%45.3%62.5%
2017–187.5%Feb 3102.741M710K52K18838%37.1%57.8%
2016–175.1%Feb 1162.029M500K38K11040%43.3%59.0%
2015–163.6%Mar 1231.524M280K22K9548%41.7%59.3%
2014–156.0%Dec 2764.030M590K51K14819%43.6%59.3%
2013–144.6%Dec 2835.230M350K38K11152%42.2%58.9%
2012–136.1%Dec 2944.034M580K43K17149%41.5%56.6%
2011–122.4%Mar 178.69.4M140K13K3747%38.8%51.5%
2010–114.6%Feb 521.723M310K38K12460%40.5%51.0%
 Peak %ILI: ILINet. Hospitalization rate: FluSurv-NET cumulative Oct–Apr. Illness, hospitalization and death estimates: CDC Disease Burden of Flu (most recent seasons preliminary). Child deaths: CDC reports. Vaccine effectiveness: U.S. Flu VE Network adjusted overall estimate. Coverage: FluVaxView end of season.
Every flu season since 2010–11, outpatient flu-like illnessUnited States, weighted %ILI. Gray lines are individual seasons; three are highlighted.
  • 2025–26
  • 2024–25, high severity
  • 2017–18, high severity
  • Other seasons
Every flu season since 2010–11, outpatient flu-like illness0%2.5%5%7.5%10%OctNovDecJanFebMarAprMayJunJulAugSepBaseline 3.1%2025–262024–252017–18

Seasons with an extra MMWR week 53 are aligned on week 40. The 2009–10 H1N1 pandemic season is excluded.

Peak weekly outpatient flu-like illness, by seasonHighest weekly national %ILI in each season.
Peak weekly outpatient flu-like illness, by season0%2.5%5%7.5%10%10–1112–1314–1516–1718–1920–2122–2324–2525–26

Hospitalizations

The best single measure of how severe a season is. 2024–25 had the highest cumulative rate since FluSurv-NET began in its current form in 2010.

Cumulative flu hospitalization rate, per 100,000 peopleFluSurv-NET, laboratory-confirmed influenza hospitalizations in selected counties of about a dozen states, October through April.
  • 2025–26
  • 2024–25
  • 2017–18
  • Typical range of other seasons
Cumulative flu hospitalization rate, per 100,000 people050100150OctNovDecJanFebMarAprMay2024–252017–182025–26

FluSurv-NET covers about 10% of the U.S. population. Rates are not adjusted for testing practices, which changed after 2020.

Cumulative hospitalization rate by season, October to AprilPer 100,000 people, FluSurv-NET, all ages.
Cumulative hospitalization rate by season, October to April05010015010–1112–1314–1516–1718–19n/a20–2122–2324–2525–26

Illnesses, hospitalizations, and deaths

CDC's modeled estimates of the full burden of flu, including people who were never tested.

Estimated symptomatic illnessesPer season, United States.
Estimated symptomatic illnesses020M40M60M10–1112–1314–1516–1718–19n/a20–2122–2324–2525–26

CDC models burden from FluSurv-NET hospitalization rates, adjusting for under-testing; final estimates for a season are published one to two years later.

Estimated flu hospitalizationsPer season, United States.
Estimated flu hospitalizations0200K400K600K800K10–1112–1314–1516–1718–19n/a20–2122–2324–2525–26

CDC models burden from FluSurv-NET hospitalization rates, adjusting for under-testing; final estimates for a season are published one to two years later.

Estimated flu deathsPer season, United States.
Estimated flu deaths020K40K60K10–1112–1314–1516–1718–19n/a20–2122–2324–2525–26

CDC models burden from FluSurv-NET hospitalization rates, adjusting for under-testing; final estimates for a season are published one to two years later.

Flu-associated deaths in children reported to CDC, by seasonLaboratory-confirmed; reporting has been nationally notifiable since 2004.
Flu-associated deaths in children reported to CDC, by season010020030012410–113717112–1311114814–159511016–1718814518–19199120–214918722–2321029724–2519525–26

About 85 to 90 percent of children who died of flu in the last two seasons, among those eligible with known status, were not fully vaccinated (CDC). The 2025–26 count is still being finalized.

Vaccination

Vaccine effectiveness against medically attended flu, by seasonAdjusted overall estimate, U.S. Flu VE Network (outpatient). Percent reduction in risk.
Vaccine effectiveness against medically attended flu, by season0%20%40%60%60%10–1147%49%12–1352%19%14–1548%40%16–1738%29%18–1939%n/a20–2136%30%22–2344%56%24–2536%25–26
Share of Americans vaccinated against flu, by seasonEnd-of-season estimates, CDC FluVaxView.
  • Adults 18+
  • Children 6 months–17 years
  • Adults 65+
Share of Americans vaccinated against flu, by season0%20%40%60%80%09–1012–1315–1618–1921–2224–2565+ChildrenAdults

Child coverage in 2024–25 was the lowest in 15 seasons.

Data: CDC ILINet (U.S. Outpatient Influenza-like Illness Surveillance Network), via Delphi Epidata API; CDC FluSurv-NET laboratory-confirmed influenza hospitalization rates, via Delphi Epidata API; CDC FluVaxView: Influenza Vaccination Coverage for All Ages (6+ Months); CDC Disease Burden of Flu, past seasons; CDC FluView Week 20, 2026 (2025–26 in-season burden); CDC Past Seasons Vaccine Effectiveness Estimates; MMWR 2025;74(6) pediatric deaths 2010–11 to 2024–25; CDC Flu and Children (2024–25 pediatric deaths); CDC FluView Week 38, 2026. Retrieved Oct 5, 2026.