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COVID -19–Associated Hospitalizations —
COVID -NET, April 2025 Update
Fiona P. Havers, MD, MHS, FIDSA
RESP -NET Hospitalization Surveillance Team
Coronavirus and Other Respiratory Viruses Division
Advisory Committee on Immunization Practices (ACIP) Meeting
April 15, 2025National Center for Immunization and Respiratory Diseases
1
COVID -NET is a population -based hospitalization
surveillance platform.
•RESP -NET: COVID -NET, RSV -NET, FluSurv -NET
•>300 acute -care hospitals
•98 counties in 13 states
•~10% of the U.S. population
•Positive SARS -CoV-2 test ≤14 days
before admission or during
hospitalization
•Screening or clinician -driven testing
•Clinical data: age - and site -stratified random sample
COVID -NET: https://www.cdc.gov/covid/php/covid -net/index.html Some slides display data from 90 counties in 12 states due to incomplete data.2
010203040
20
2020
2120
2220
2320
2420
25Rates of COVID -19, influenza, and RSV hospitalization — RESP -NET, 2020 –2025
2020 2021 2022 2023 2024 2025COVID -19 hospitalization rates have had both winter
and summer peaks.
30246810121416Hospitalizations per 100,000 populationWeekly Rates of COVID -19–, Influenza -, and RSV -Associated
Hospitalizations — RESP -NET, October 2023 –March 2025
COVID-19 Influenza RSV
Rates for all three pathogens (COVID -19, influenza, and respiratory syncytial virus [RSV]) are laboratory -confirmed. Data source : https://www.cdc.gov/resp -net/dashboard/
Note that rates are not adjusted for testing or limited to admissions where the respiratory infection is the likely primary r eason for admission.
Rates of COVID -19 hospitalizations for the 2024 –2025
season are lower compared to last season.
4050100150200250
Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug SepHospitalizations per 100,000 populationCumulative Rates of COVID -19–, Influenza -, and RSV -Associated Hospitalizations, by Surveillance Season* —
RESP -NET, October 2023 –March 2025
COVID 2023 –2024 Influenza 2023 –2024 RSV 2023 –2024
COVID 2024 –2025 Influenza 2024 –2025 RSV 2024 –2025
* Seasons are defined as October through September. The 2024 –2025 season shows data from October 2024 –March 2025 and is ongoing.
Rates for all three pathogens (COVID -19, influenza, and respiratory syncytial virus [RSV]) are laboratory -confirmed. Data source : https://www.cdc.gov/resp -net/dashboard/
Note that rates are not adjusted for testing or limited to admissions where the respiratory infection is the likely primary r eason for admission.
Cumulative COVID -19–associated hospitalization rates by
surveillance season — COVID -NET, March 2020 –March 2025
* The 2019 –2020 surveillance period includes March –September 2020; other seasons are defined as October through September. The 2 024–2025 season shows data from October 2024 –
March 2025 and is ongoing. 50100200300400500600
2019 –2020 2020 –2021 2021 –2022 2022 –2023 2023 –2024 2024 –2025Hospitalization rate per 100,000 population
Respiratory virus season*May–September
October –April
Many COVID -19-
associated
hospitalizations
occur outside of
the typical
respiratory virus
season.
Among all age groups, rates of COVID -19–associated
hospitalizations have declined since the 2021 –2022 season.
* The 2019 –2020 surveillance period includes March –September 2020; other seasons are defined as October through September. The 2 024–2025 season shows data from October 2024 –
March 2025 and is ongoing.
6050010001500200025003000
*2019 –2020
2020 –2021
2021 –2022
2022 –2023
2023 –2024
2024 –2025
*2019 –2020
2020 –2021
2021 –2022
2022 –2023
2023 –2024
2024 –2025
*2019 –2020
2020 –2021
2021 –2022
2022 –2023
2023 –2024
2024 –2025
*2019 –2020
2020 –2021
2021 –2022
2022 –2023
2023 –2024
2024 –2025
*2019 –2020
2020 –2021
2021 –2022
2022 –2023
2023 –2024
2024 –2025
*2019 –2020
2020 –2021
2021 –2022
2022 –2023
2023 –2024
2024 –2025
*2019 –2020
2020 –2021
2021 –2022
2022 –2023
2023 –2024
2024 –2025
*2019 –2020
2020 –2021
2021 –2022
2022 –2023
2023 –2024
2024 –2025
<6 mo 6 mo –4 yrs 5–11 yrs 12–17 yrs 18–49 yrs 50–64 yrs 65–74 yrs ≥75 yrsRate per 100,000 population
Age group and surveillance periodCumulative rates of COVID -19–associated hospitalizations — COVID -NET, March 2020 –March 2025
Rates of respiratory virus -associated hospitalizations vary
by age group and pathogen.
70200400600800100012001400160018002000
<1 1–4 5–11 12–17 18–49 50–64 65–74 ≥75Rate per 100,000 population
Age in yearsCumulative rates of COVID -19–, influenza -, and RSV -associated hospitalizations —
RESP -NET, October 2023 –September 2024
COVID-19 Influenza RSV
Rates for all three pathogens (COVID -19, influenza, and respiratory syncytial virus [RSV]) are laboratory -confirmed. Data source : https://www.cdc.gov/resp -net/dashboard/
Note that rates are not adjusted for testing or limited to admissions where the respiratory infection is the likely primary r eason for admission.
Pediatric COVID -19–Associated
Hospitalizations
8
During 2024 –2025, children and adolescents comprised
about 4% of COVID -19–associated hospitalizations.
90%10%20%30%40%50%60%70%80%90%100%Percent of COVID -19–associated hospitalizations
Surveillance week end datePercent of monthly COVID -19–associated hospitalizations, by age group —
COVID -NET, March 2020 –March 2025
≤4 years 5–11 years 12–17 years 18–49 years 50–64 years 65–74 years ≥75 years•≤17 years = 4.3% of
COVID -19–associated
hospitalizations
during October 2024 –
March 2025
•≤4 years = 2.9%
•5–11 years = 0.6%
•12–17 years = 0.6%
Among all children and adolescents, rates of COVID -19–associated
hospitalizations are highest among infants ages <6 months.
10051015202530Rate per 100,000 population
Surveillance week end dateWeekly rates of COVID -19–associated hospitalizations among children and adolescents ages ≤17 years — COVID -NET, October
2022 –March 2025
<6 months 6 months –4 years 5–11 years 12–17 yearsMarch 2020 –March 2025
Among all children and adolescents, rates of COVID -19
hospitalizations are highest among infants ages <6 months.
11051015202530Rate per 100,000 population
Surveillance week end dateWeekly rates of COVID -19–associated hospitalizations among children and adolescents ages 6 months —17 years —
COVID -NET, October 2022 –March 2025
6 months –4 years 5–11 years 12–17 yearsMarch 2020 –March 2025
Among children and adolescents eligible for COVID -19 vaccines,
cumulative rates of COVID -19–associated hospitalizations
remain the highest among children ages 6 months –4 years.
1201234Rate per 100,000 population
Surveillance week end dateWeekly rates of COVID -19–associated hospitalizations — COVID -NET, October 2022 –March 2025
6 months –4 years 5–11 years 12–17 yearsMarch 2020 –March 2025
Rates* of influenza and COVID -19–associated hospitalizations
among children ages ≤17 years** — RESP -NET, 2014 –2024
* Note that rates of influenza hospitalizations are adjusted for undertesting and under -detection. Rates of COVID -19 hospitaliza tions are not adjusted for undertesting
or under -detection. Rates of COVID -19 hospitalization might be higher when adjusted for these factors.
** Monitoring for influenza hospitalizations typically occurs during October through April; for COVID -19 hospitalizations, monit oring for a given respiratory season
begins in October and continues through the following September. For the 2019 –2020 period, monitoring for COVID -19 hospitalizati ons began in March 2020.
Historical flu data from https://www.cdc.gov/flu -burden/php/data -vis/past -seasons.html . Historical flu data are not available for the 2020 –2021 period. 13050100150200250
2014 –2015
2015 –2016
2016 –2017
2017 –2018
2018 –2019
2019 –2020
2020 –2021
2021 –2022
2022 –2023
2023 –2024
2014 –2015
2015 –2016
2016 –2017
2017 –2018
2018 –2019
2019 –2020
2020 –2021
2021 –2022
2022 –2023
2023 –2024
0–4 years 5–17 yearsHospitalization rates per 100,000
populationInfluenza
COVID-19
Among children ages ≤4 years, COVID -19–associated
hospitalization rates during the 22 –23 and 23 –24 seasons were
similar to those due to influenza.
* Note that rates of influenza hospitalizations are adjusted for undertesting and under -detection. Rates of COVID -19 hospitaliza tions are not adjusted for undertesting
or under -detection. Rates of COVID -19 hospitalization might be higher when adjusted for these factors.
** Monitoring for influenza hospitalizations typically occurs during October through April; for COVID -19 hospitalizations, monit oring for a given respiratory season
begins in October and continues through the following September. For the 2019 –2020 period, monitoring for COVID -19 hospitalizati ons began in March 2020.
Historical flu data from https://www.cdc.gov/flu -burden/php/data -vis/past -seasons.html . Historical flu data are not available for the 2020 –2021 period. 14050100150200250
2014 –2015 2015 –2016 2016 –2017 2017 –2018 2018 –2019 2019 –2020 2020 –2021 2021 –2022 2022 –2023 2023 –2024
0–4 yearsHospitalization rates per 100,000 populationRates* of influenza and COVID -19–associated hospitalizations among children ages 0 –4 years,
by season** — RESP -NET, 2014 –2024
Influenza
COVID-19
Among children aged 5 –17 years, COVID -19–associated
hospitalization rates during the 22 –23 and 23 –24 seasons were
lower than those due to influenza.
* Note that rates of influenza hospitalizations are adjusted for undertesting and under -detection. Rates of COVID -19 hospitaliza tions are not adjusted for undertesting
or under -detection. Rates of COVID -19 hospitalization might be higher when adjusted for these factors.
** Monitoring for influenza hospitalizations typically occurs during October through April; for COVID -19 hospitalizations, monit oring begins in October and is conducted
year -round. For the 2019 –2020 period, monitoring for COVID -19 hospitalizations began in March 2020.
Historical flu data from https://www.cdc.gov/flu -burden/php/data -vis/past -seasons.html . Historical flu data are not available for the 2020 –2021 period. 15010203040506070
2014 –2015 2015 –2016 2016 –2017 2017 –2018 2018 –2019 2019 –2020 2020 –2021 2021 –2022 2022 –2023 2023 –2024
5–17 yearsHospitalization rates per 100,000
populationRates* of influenza and COVID -19–associated hospitalizations among children ages 5 – ≤17 years, and
season** — RESP -NET, 2014 –2024
Influenza
COVID-19
During October 2022 –April 2024, more older children hospitalized
with COVID -19 had underlying medical conditions compared with
younger age groups.
16010203040
6–23 months 2–4 years 5–11 years 12–17 yearsWeighted % of COVID -19–associated hospitalizations
Prematurity* Asthma/Reactive airway disease Neurologic disorders
Obesity† Chronic lung disease, not including asthma Feeding tube dependence
Cardiovascular disease Immunocompromising conditions Blood disorders
Chronic metabolic diseases, including diabetes77% with ≥1
underlying
condition42% with ≥1
underlying
condition62% with ≥1
underlying
condition79% with ≥1
underlying
condition
* Prematurity is only assessed for children aged <2 years. †Obesity is not calculated for children aged <2 years. Data are li mited to hospitalizations with COVID -19 as the likely
reason for admission. Source: Pre -publication analysis from Rebecca Free and presented at IDWeek 2024. Data reflect the period of October 1, 2022 –April 30, 2024.
Among children and adolescents ages 6 months –17 years hospitalized with COVID -19,
59% had ≥1 underlying condition.
~1 in 5 children and adolescents with COVID -19–associated
hospitalization are admitted to the intensive care unit (ICU)
Hospitalizations are limited to those with COVID -19 as the presenting complaint upon admission.212223
2127
051015202530
<6 months 6 months –<2
years2–4 years 5–11 years 12–17 yearsPercent of hospitalizationsPercent of children and adolescents with COVID -19–
associated hospitalizations admitted to the ICU,
by age group — COVID -NET, July 2023 –March 2024
During this period, 7 children with COVID -19–
associated hospitalization died in -hospital in the
COVID -NET catchment area. Age categoryAmong those
admitted to
ICU, % with no
underlying
conditions
<6 months 56%
6–23 months 52%
2–4 years 30%
5–11 years 6%
12–17 years 24%
41% of children admitted to the ICU
had no underlying conditions, but this
varied by age group
Fewer than 5% of children and adolescents eligible to received
COVID -19 vaccinations and hospitalized with COVID -19 received
the most recently recommended COVID -19 vaccination.
No record of COVID -19 dose in past 12 months : No recorded doses of any COVID -19 vaccine dose in the 12 months preceding hospitalization . ≥1 vaccine dose in
last 12 months, but no 2023 –2024 dose: Received at least one COVID -19 bivalent booster vaccination in the 12 months preceding hospitalizations, but no record of
receiving 2023 -2024 vaccine dose. 2023 –2024 vaccine dose: Received 2023 -2024 vaccine dose. Persons with unknown vaccination status are
excluded. Hospitalizations are limited to those with COVID -19 as the presenting complaint upon admission.90 9092
8 73 2 35
0102030405060708090100
6 months –4 years 5–11 years 12–17 yearsPercent of hospitalizationsVaccination status among children and adolescents with COVID -19–associated hospitalizations,
by age group — COVID -NET, October 2023 –September 2024
No record of COVID-19 vaccine in past 12 months ≥1 vaccine dose in last 12 months, but no 2023 –2024 dose 2023 –2024 dose
Summary (Children and Adolescents)
•Rates of COVID -19–associated hospitalizations are highest among youngest age groups.
•Among children and adolescents ages 5 –17 years, rates of hospitalization are higher for
influenza than COVID -19.
•More than half (59%) of children and adolescents hospitalized with COVID -19 had ≥1
underlying medical condition.
-Proportion of children with ≥1 underlying condition increased with age.
•Most common underlying conditions among children and adolescents hospitalized with
COVID -19 varied by age group.
•Fewer than 5% of children and adolescents hospitalized with COVID -19 had received the
most recently recommended COVID -19 vaccination during the 23 -24 season.
19
COVID -19–Associated Hospitalizations
Among Adults Ages ≥18 Years
20
Adults ages ≥65 years comprise more than 2/3 of all
COVID -19–associated hospitalizations among adults.
During this same period of January 2024 through March 2025, children and adolescents ages 17 years and younger comprised 4% o f all COVID -19-associated hospitalizations.210%10%20%30%40%50%60%70%80%90%100%
3/7/2020
5/30/2020
8/22/2020
11/14/2020
2/6/2021
5/1/2021
7/24/2021
10/16/2021
1/8/2022
4/2/2022
6/25/2022
9/17/2022
12/10/2022
3/4/2023
5/27/2023
8/19/2023
11/11/2023
2/3/2024
4/27/2024
7/20/2024
10/12/2024
1/4/2025
2/22/2025Percent of adults hospitalized with COVID -19
Surveillance week end datePercent of weekly COVID -19–associated hospitalizations among
adults ages ≥18 years, by age group —
COVID -NET, March 2020 –March 2025
18–49 years 50–64 years 65–74 years ≥75 years≥75 years=48%
≥65 years=68%
Among adults, rates of COVID -19–associated
hospitalizations increase with age.
22581624191410
02004006008001000120014001600Rate per 100,000 population
Surveillance week end dateCumulative rates of COVID -19–associated hospitalizations — COVID -NET, October 2023 –September
2024
18–49 years 50–64 years 65–74 years ≥75 yearsAge groupRate ratio
of ≥75
years
relative to
adult age
groups
18–49 24.4
50–64 8.7
65–74 3.4
Rates among adults ages
≥75 years are many times
higher compared to
younger adults.
Among adults ages ≥65 years, rates of COVID -19–associated
hospitalization during recent years remained higher than rates
of influenza –associated hospitalization.
* Note that rates of influenza hospitalization for 2014 –2015 through 2023 –2024 are adjusted for undertesting and under -detection . Rates of influenza hospitalizations for 2024 –2025 (shown in
lighter colors) and all COVID -19 hospitalizations are not adjusted for undertesting or under -detection. Rates of hospitalization might be higher when adjusted for these factors.
** Monitoring for influenza hospitalizations typically occurs during October through April; for COVID -19 hospitalizations, monit oring begins in October and is conducted year -round. For the 2019 –
2020 period, monitoring for COVID -19 hospitalizations began in March 2020.
*** Data for 2024 -2025 show data for October 2024 – March 2025 only as the season is ongoing.
Historical flu data from https://www.cdc.gov/flu -burden/php/data -vis/past -seasons.html . Historical flu data are not available for the 2020 –2021 period. 23020040060080010001200140016001800
2014 –2015
2015 –2016
2016 –2017
2017 –2018
2018 –2019
2019 –2020
2020 –2021
2021 –2022
2022 –2023
2023 –2024
2024 –2025***
2014 –2015
2015 –2016
2016 –2017
2017 –2018
2018 –2019
2019 –2020
2020 –2021
2021 –2022
2022 –2023
2023 –2024
2024 –2025***
2014 –2015
2015 –2016
2016 –2017
2017 –2018
2018 –2019
2019 –2020
2020 –2021
2021 –2022
2022 –2023
2023 –2024
2024 –2025***
18–49 years 50–64 years ≥65 yearsHospitalization rates per 100,000
populationRates* of influenza and COVID -19–associated hospitalizations among adults
ages ≥18 years, by age group and season** — RESP -NET, 2014 –2025
Influenza COVID-19
Risk for COVID -19–associated hospitalization is increased
among community -dwelling adults ages ≥18 years with
underlying medical conditions.
Abbreviations: RR, rate ratio; CI, confidence interval; COPD, chronic obstructive pulmonary disease.
* “None” refers to having none of the conditions examined in this analysis ( asthma, COPD, diabetes, chronic kidney disease, coronary artery disease, stroke, severe obesity, and current smoking).
** “Any condition” refers to having at least 1 of these conditions. Notes: Non -severe obesity is defined as BMI 30 –39kg/m². Severe obesity is defined as BMI ≥40kg/m². “Any condition” includes
asthma, COPD, diabetes, chronic kidney disease, coronary artery disease, stroke, severe obesity, and current smoking. Rate ra tios were estimated using multivariable Poisson models adjusted for sex,
and race/ethnicity. “Smoker (current)” Includes people who quit smoking within the past 12 months. Data are limited to hospit alizations where COVID -19 is the likely reason for admission. 240.1110100
None* Any
condition**Asthma COPD Chronic
kidney
diseaseCoronary
artery
diseaseDiabetes Stroke
(history of)Obesity
(non-severe)Obesity
(severe)Smoker
(current)Adjusted RR (log scale)Adjusted Rate Ratios for COVID -19–associated Hospitalizations among Community -Dwelling Adults Ages ≥18 Years,
by Age Group — October 2022 –September 2023
18–49 50–64 65–74 ≥75Patterned bars indicate CIs that include 1.0.
~1 in 5 adults hospitalized due to COVID -19 were admitted to the
intensive care unit (ICU)
251822
18
613
8
211
8
0510152025
18–49 years 50–64 years ≥65 yearsPercent of adults hospitalized with
COVID -19
Age groupProportion of adults hospitalized with COVID -19 with interventions and outcomes,
by age group — COVID -NET, October 2023 –May 2024
ICU admission Invasive mechical ventilation In-hospital death
Data are limited to hospitalizations where COVID -19 is a likely primary reason for admission. Deaths do not include other COVID -19-related deaths that might occur after a patient is
discharged to hospice or other deaths that occur soon after hospital discharge that could be attributable to COVID -19-related il lness. During this period, 80% of all adults hospitalized with COVID -19 who died in -hospital were ages ≥65 years.
Most adults hospitalized with COVID -19 had received no COVID -19
vaccine since September 2022.
Data are limited to hospitalizations where COVID -19 is a likely primary reason for admission.2675
6165
4150
1927
202523
7121533
26
01020304050607080
18–49 50–64 65–74 ≥75 ≥65Percent of adults hospitalized with COVID -19
Age group in yearsVaccination status among adults hospitalized with COVID -19, by age group —
COVID -NET, October 2023 –September 2024
No record of 2022 –2023 (bivalent) or 2023 –2024 formula
Received 2022 –2023 (bivalent), but not 2023 –2024 formula
Received 2023 –2024 formula
As of November 30,
2024, only 30% of
nursing home
residents had
received a 2024 –2025
COVID -19 vaccine.
2758
30
18
010203040506070
Influenza COVID-19 RSV% nursing home residents vaccinated
* As of December 10, 2024. Reses et al. “Coverage with Influenza, Respiratory Syncytial Virus, and Updated COVID -19 Vaccines Amo ng Nursing Home Residents - National Healthcare Safety Network, United
States, November 2024“. MMWR, November 21, 2024.
Summary (Adults) (slide 1 of 2)
•Rates of COVID -19–associated hospitalizations are highest among oldest adult age
groups.
•Adults aged ≥65 years comprise 68% of adult COVID -19–associated
hospitalizations
-Aged ≥75 years: 48% of adult hospitalizations
•COVID -19-associated hospitalization rates decreased over time, but cumulative
rates among adults aged ≥75 years for the 2023 -2024 season remained higher
than those experienced by any other adult age group for any previous season.
•Risk of hospitalization with COVID -19 remains during summer months (May –Sept).
•26% of adults ages ≥65 years hospitalized with COVID -19 received the
recommended 2023 -24 COVID -19 vaccine prior to hospitalization.
28
Summary (Adults) (slide 2 of 2)
•Some underlying medical conditions increase the risk for COVID -19
hospitalization among adults
-CKD, diabetes, and CAD increased risk in all adult age groups
•Having none of the underlying medical conditions examined decreased the risk
for COVID -19–associated hospitalization across all adult age groups.
•In general, the relative risk of COVID -19 hospitalization among adults with vs.
without select conditions declined with age for most, but not all, conditions
examined.
Abbreviations: CKD: chronic kidney disease; CAD: coronary artery disease; COPD: chronic obstructive pulmonary disease.29