Hospitalizations of Children and Adolescents With Laboratory-Confirmed COVID-19

COVID-NET, 14 States, July 2021-January 2022

Kristin J. Marks, PhD; Michael Whitaker, MPH; Onika Anglin, MPH; Jennifer Milucky, MSPH; Kadam Patel, MPH; Huong Pham, MPH; Shua J. Chai, MD; Pam Daily Kirley, MPH; Isaac Armistead, MD; Sarah McLafferty, MPH; James Meek, MPH; Kimberly Yousey-Hindes, MPH; Evan J. Anderson, MD; Kyle P. Openo, DrPH; Andy Weigel, MSW; Justin Henderson, MPH; Val Tellez Nunez, MPH; Kathryn Como-Sabetti, MPH; Ruth Lynfield, MD; Susan L. Ropp, PhD; Chad Smelser, MD; Grant R. Barney, MPH; Alison Muse, MPH; Nancy M. Bennett, MD; Sophrena Bushey, MHS; Laurie M. Billing, MPH; Eli Shiltz, MPH; Nasreen Abdullah, MD; Melissa Sutton, MD; William Schaffner, MD; H. Keipp Talbot, MD; Ryan Chatelain, MPH; Andrea George, MPH; Christopher A. Taylor, PhD; Meredith L. McMorrow, MD; Cria G. Perrine, PhD; Fiona P. Havers, MD

Disclosures

Morbidity and Mortality Weekly Report. 2022;71(7):271-278.

Discussion

The Omicron variant, which is associated with increased transmissibility and partial escape from infection- or vaccine-induced immunity, replaced Delta as the predominant variant in the United States in late December 2021.^[1] Once the Omicron variant became predominant, peak population-based COVID-19–associated hospitalization rates among children and adolescents were four times as high as rates during the peak of the Delta period. Children aged 0–4 years, who were ineligible for vaccination during this time, experienced the largest increase in hospitalization rates. Observed indicators of severe COVID-19 among children and adolescents, in addition to the potential for longer-term sequelae,^[4,5] highlight the importance of multicomponent strategies to reduce the incidence of COVID-19, including vaccination of eligible persons and other prevention measures.^{†††††}

Among adolescents aged 12–17 years, the only pediatric age group for whom a COVID-19 vaccine was approved throughout the study period, December hospitalization rates among unvaccinated adolescents were approximately six times those among fully vaccinated adolescents, suggesting that vaccines were highly effective in preventing serious COVID-19 illness. Vaccination eligibility was expanded to include children aged 5–11 years on November 2, 2021. As of December 31, 2021, 54% of the population aged 12–17 years and 16% of those aged 5–11 years had completed a COVID-19 primary vaccination series.^§§§§§ Increasing vaccination coverage among both age groups can reduce COVID-19–associated hospitalizations;^[6] enhanced outreach strategies are needed to address disparities in vaccination coverage by race/ethnicity.

Consistent with national hospital surveillance data,^[7] the findings in this report indicate that the Omicron-predominant period had higher rates of pediatric COVID-19 hospitalizations than the Delta-predominant period. No differences were found between the Delta- and Omicron-predominant periods in the proportion of hospitalizations that were likely to be related to COVID-19. Findings suggest that incidental admissions do not account for the increase in hospitalization rates observed during the Omicron period. Throughout the COVID-19 pandemic, admissions for reasons other than COVID-19 have been recorded,^[8,9] and during both the Delta- and Omicron-predominant periods, incidental admissions were more likely among fully vaccinated adolescents. Reasons for admission should continue to be monitored as more children and adolescents become fully vaccinated.

The findings in this report are subject to at least six limitations. First, COVID-19–associated hospitalizations might have been missed because of testing practices and test availability. Second, the period of Omicron variant predominance with available detailed clinical data is brief (December 19–31, 2021) and does not capture the peak of hospitalizations during the Omicron period; in addition, the Delta variant was still circulating in late December. Third, accounting for seasonality in comparisons of Delta and Omicron predominant periods was not possible. Fourth, the number of hospitalized children eligible for vaccination remained low at the time of reporting, and hospitalization rates stratified by vaccination status are subject to error if misclassification of vaccination status occurred. Fifth, because children aged 5–11 years could not meet the definition for being fully vaccinated until December 7, 2021, vaccination among this age group was not considered in this study. However, vaccinations could have affected hospitalization rates during the Omicron period. Further, boosters among adolescents aged 12–17 years could not be examined because the recommendation was so recent. Finally, the COVID-NET catchment areas include approximately 10% of the U.S. population; thus, these findings might not be generalizable to the entire United States.

Coinciding with emerging predominance of the Omicron variant, rates of COVID-19–associated hospitalization among children and adolescents increased rapidly during the last 2 weeks of December 2021, especially among those aged 0–4 years. Moreover, among adolescents, hospitalization rates were higher among those who were unvaccinated. Vaccination of eligible persons, in addition to other prevention strategies such as masking, are critical to reducing the incidence of severe COVID-19 among children and adolescents.^¶¶¶¶¶ All persons who are eligible for vaccination should receive and stay up to date with COVID-19 vaccines to reduce the risk for severe disease for themselves and others with whom they come into contact, including children who are currently too young to be vaccinated.******

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Acknowledgments
Joelle Nadle, Sherry Quach, Jeremy Roland, Gretchen Rothrock, California Emerging Infections Program, Oakland, California; Rachel Herlihy, Madelyn Lensing, Jordan Surgnier, Millen Tsegaye, Colorado Department of Public Health and Environment; Ann Basting, Tessa Carter, Daewi Kim, Julie Plano, Connecticut Emerging Infections Program, Yale School of Public Health; Marina Bruck, Rayna Ceaser, Gracie Chambers, Taylor Eisenstein, Sabrina Hendrick, Johanna Hernandez, Asmith Joseph, Grayson Kallas, Stephanie Lehman, Jana Manning, Annabel Patterson, Allison Roebling, Suzanne Segler, Chandler Surell, Hope Wilson, School of Medicine, Emory University, Georgia Emerging Infections Program, Georgia Department of Public Health, Veterans Affairs Medical Center, Foundation for Atlanta Veterans Education and Research, Atlanta, Georgia; Chloe Brown, Jim Collins, Shannon Johnson, Sue Kim, Alexander Kohrman, Lauren Leegwater, Sierra Peguies-Khan, Libby Reeg, Michigan Department of Health and Human Services; Alison Babb, Richard Danila, Kristen Ehresmann, Jake Garfin, Jennifer Gilbertson, Grace Hernandez, Melissa McMahon, Kieu My Phi, Jill Reaney, Sara Vetter, Xiong Wang, Minnesota Department of Health; Cory Cline, Melissa Judson, Sunshine Martinez, Florent Nkouaga, Jasmyn Sanchez, Daniel Sosin, New Mexico Department of Health; Kathy M. Angeles, Molly Bleecker, Sarah Shrum Davis, Nancy Eisenberg, Sarah A. Khanlian, Sarah Lathrop, Wickliffe Omondi, Mayvilynne Poblete, Dominic Rudin, Yadira Salazar-Sanchez, New Mexico Emerging Infections Program; Jennifer Akpo, Celina Chavez, Yassir Talha, Alesia Reed, CDC Foundation, New Mexico Department of Health; Kerianne Engesser, Suzanne McGuire, New York State Department of Health; Christina Felsen, Maria Gaitan, Christine Long, Thomas Peer, University of Rochester School of Medicine and Dentistry; Julie Freshwater, Denise Ingabire-Smith, Ann Salvator, Rebekah Sutter, Ohio Department of Health; Kathy Billings, Katie Dyer, Anise Elie, Gail Hughett, Karen Leib, Terri McMinn, Danielle Ndi, Manideepthi Pemmaraju, Emmanuel Sackey, Vanderbilt University Medical Center; Ian Buchta, Amanda Carter, Melanie Crossland, Andrew Haraghey, Mary Hill, Laine McCullough, Jake Ortega, Tyler Riedesel, Caitlin Shaw, Ashley Swain, Salt Lake County Health Department, Salt Lake City, Utah; Rainy Henry, Sonja Mali Nti-Berko, Robert W. Pinner, Alvin Shultz, CDC; Mimi Huynh, Council of State and Territorial Epidemiologists.

^{†††††} https://www.cdc.gov/vaccines/hcp/acip-recs/vacc-specific/covid-19.html
^§§§§§ https://covid.cdc.gov/covid-data-tracker/#vaccination-demographics-trends
^¶¶¶¶¶ https://www.cdc.gov/coronavirus/2019-ncov/variants/omicron-variant.html
******https://www.cdc.gov/coronavirus/2019-ncov/vaccines/stay-up-to-date.html

Table 1. Demographic and clinical characteristics and outcomes among children and adolescents aged 0–17 years with laboratory-confirmed COVID-19–associated hospitalizations,* by date of admission — COVID-NET, 14 states, ^† July 1–December 31, 2021
Characteristic	No. of hospitalized children (%)			p-value^§
	Total	Jul 1–Dec 18	Dec 19–31
	Jul 1–Dec 31	Jul 1–Dec 18	Dec 19–31
Total	2,100 (100.0)^¶	1,834 (82.3)^¶	266 (17.7)^¶	—
Age, yrs, median (IQR)	7 (1–14)	7 (1–14)	3.5 (0.4–13)	<0.001
Age group, yrs
0–4	920 (44.6)	778 (42.5)	142 (54.2)	0.003
5–11	460 (21.5)	417 (22.5)	43 (16.9)
12–17	720 (33.9)	639 (34.9)	81 (28.9)
Sex
Male	1,081 (51.7)	934 (51.2)	147 (54.2)	0.38
Female	1,019 (48.3)	900 (48.8)	119 (45.8)	0.38
Race and ethnicity**
Hispanic	463 (21.8)	420 (23.1)	43 (15.7)	<0.001
Black, non-Hispanic	736 (35.8)	619 (33.4)	117 (47.1)
White, non-Hispanic	670 (31.3)	598 (32.6)	72 (25.5)
Asian or Pacific Islander, non-Hispanic	82 (3.9)	71 (3.9)	11 (3.7)
All other races^††	47 (2.3)	41 (2.3)	6 (2.1)
Unknown race and ethnicity	102 (5.0)	85 (4.8)	17 (5.9)
Primary reason for admission^§§
Likely related to COVID-19	1,703 (81.3)	1,489 (81.3)	214 (81.6)	0.19
Obstetrics	63 (2.9)	57 (3.0)	6 (2.2)
Inpatient surgery	53 (2.6)	43 (2.5)	10 (3.3)
Psychiatric admission requiring medical care	118 (5.6)	108 (5.9)	10 (4.0)
Trauma	75 (3.5)	67 (3.7)	8 (2.8)
Other reason	78 (3.8)	62 (3.3)	16 (6.1)
Unknown reason	6 (0.3)	6 (0.3)	0 (—)
COVID-19–related symptoms at admission^¶¶
Yes	1,832 (87.6)	1,604 (87.7)	228 (86.9)	0.72
No	264 (12.4)	228 (12.3)	36 (13.1)	0.72
Hospitalization outcomes
Length of hospital stay, days, median (IQR)	3 (1–5)	3 (2–5)	2 (1–5)	0.15
ICU admission***	562 (26.4)	510 (27.8)	52 (20.2)	0.01
Invasive mechanical ventilation***	118 (5.6)	112 (6.3)	6 (2.3)	0.01
In-hospital death	11 (0.5)	11 (0.6)	0 (—)	0.38
Vaccination status (among patients aged 12–17 yrs)
Fully vaccinated^†††	71 (9.9)	53 (8.3)	18 (22.2)	<0.001
Unvaccinated	647 (90.1)	584 (91.7)	63 (77.8)	<0.001

Abbreviations: COVID-NET = Coronavirus Disease 2019–Associated Hospitalization Surveillance Network; ICU = intensive care unit.
*Data are from a weighted sample of hospitalized children and adolescents with completed medical record abstractions. Sample sizes presented are unweighted with weighted percentages.
^†Includes persons admitted to a hospital with an admission date during July 1–December 31, 2021. Maryland contributed data through November 26, 2021. Counties included in COVID-NET surveillance: California (Alameda, Contra Costa, and San Francisco counties); Colorado (Adams, Arapahoe, Denver, Douglas, and Jefferson counties); Connecticut (Middlesex and New Haven counties); Georgia (Clayton, Cobb, DeKalb, Douglas, Fulton, Gwinnett, Newton, and Rockdale counties); Iowa (one county represented); Maryland (Allegany, Anne Arundel, Baltimore, Baltimore City, Calvert, Caroline, Carroll, Cecil, Charles, Dorchester, Frederick, Garrett, Harford, Howard, Kent, Montgomery, Prince George's, Queen Anne's, St. Mary's, Somerset, Talbot, Washington, Wicomico, and Worcester counties); Michigan (Clinton, Eaton, Genesee, Ingham, and Washtenaw counties); Minnesota (Anoka, Carver, Dakota, Hennepin, Ramsey, Scott, and Washington counties); New Mexico (Bernalillo, Chaves, Doña Ana, Grant, Luna, San Juan, and Santa Fe counties); New York (Albany, Columbia, Genesee, Greene, Livingston, Monroe, Montgomery, Ontario, Orleans, Rensselaer, Saratoga, Schenectady, Schoharie, Wayne, and Yates counties); Ohio (Delaware, Fairfield, Franklin, Hocking, Licking, Madison, Morrow, Perry, Pickaway, and Union counties); Oregon (Clackamas, Multnomah, and Washington counties); Tennessee (Cheatham, Davidson, Dickson, Robertson, Rutherford, Sumner, Williamson, and Wilson counties); and Utah (Salt Lake County).
^§Proportions between the Delta and Omicron predominance periods were compared with chi-square tests or Fisher's exact tests (as appropriate), and medians were compared with the Wilcoxon rank-sum test; p-values <0.05 were considered statistically significant.
^¶Data are missing for <5% of observations for all variables.
**If ethnicity was unknown, non-Hispanic ethnicity was assumed.
^††Includes non-Hispanic persons reported as other or multiple races.
^§§Among sampled patients, COVID-NET collects data on the primary reason for admission to differentiate hospitalizations of patients with laboratory-confirmed SARS-CoV-2 infection who are likely admitted primarily for COVID-19 illness rather than for other reasons. During chart review, if the surveillance officer finds that the chief complaint or history of present illness mentions fever or respiratory illness, COVID-19–like illness, or suspected COVID-19, then the case is categorized as COVID-19–related illness as the primary reason for admission. Reasons for admission that are likely primarily not related to COVID-19 include the following categories: obstetrics/labor and delivery, inpatient surgery or procedures, psychiatric admission requiring acute medical care, trauma, other, or unknown. Reasons categorized as "other" are reviewed by two physicians to determine whether the admission is likely COVID-19 related.
^¶¶COVID-19–related symptoms included respiratory symptoms (congestion or runny nose, cough, hemoptysis or bloody sputum, shortness of breath or respiratory distress, sore throat, upper respiratory infection, influenza-like illness, and wheezing) and nonrespiratory symptoms (abdominal pain, altered mental status or confusion, anosmia or decreased smell, chest pain, conjunctivitis, diarrhea, dysgeusia or decreased taste, fatigue, fever or chills, headache, muscle aches or myalgias, nausea or vomiting, rash, and seizures), and among those aged <2 years, included apnea, cyanosis, decreased vocalization or stridor, dehydration, hypothermia, inability to eat or poor feeding, and lethargy. Symptoms are abstracted from the medical chart and might not be complete.
***ICU admission and invasive mechanical ventilation are not mutually exclusive categories, and patients could have received both.
^†††Fully vaccinated adolescents with COVID-19–associated hospitalizations were defined as those who had received the final dose in their primary series ≥14 days before receiving a positive SARS-CoV-2 test result associated with their hospitalization. Adolescents who received only 1 vaccine dose ≥14 days before the SARS-CoV-2 test date or had received a single dose of vaccine <14 days before the positive SARS-CoV-2 test results were considered partially vaccinated; they were not included in rates and were grouped with unvaccinated adolescents in other analyses. COVID-NET sites, through agreements with state health departments and other partners, collect COVID-19 vaccination information on COVID-19–associated hospitalizations through state-based vaccine registries. When possible, sites collect COVID-19 vaccination status on all persons with COVID-19 cases who are hospitalized, including the number of vaccine doses received, the vaccine product, and dates of vaccination administration.

Table 2. Demographic and clinical characteristics and outcomes among fully vaccinated* and unvaccinated adolescents aged 12–17 years with laboratory-confirmed COVID-19–associated hospitalizations, ^† by date of admission — COVID-NET, 14 states, ^§ July 1–December 31, 2021
Characteristic	No. of hospitalized adolescents (%)
	Unvaccinated	Vaccinated	p-value^¶	Unvaccinated		Vaccinated
	Total			Unvaccinated		Vaccinated
	Jul 1–Dec 31			Jul 1–Dec 18	Dec 19–31	Jul 1–Dec 18	Dec 19–31
Total	647 (100.0)**	71 (100.0)**	—	584 (90.2)**	63 (9.8)**	53 (74.6)**	18 (25.4)**
Age, yrs, median (IQR)	15 (14–16)	15 (14–16)	0.75	15 (14–17)	14 (13–16)	15 (14–16)	15 (14–16)
Sex
Male	298 (46.0)	25 (35.2)	0.08	266 (45.5)	32 (50.8)	20 (37.7)	5 (27.7)
Female	349 (54.0)	46 (64.8)	0.08	318 (54.5)	31 (49.2)	33 (62.3)	13 (72.3)
Race and ethnicity^††
Hispanic	148 (22.9)	14 (19.7)	0.006	136 (23.3)	12 (19.0)	12 (22.6)	2 (11.1)
Black, non-Hispanic	274 (42.4)	17 (24.0)		240 (41.1)	34 (53.9)	11 (20.8)	6 (33.4)
White, non-Hispanic	162 (25.0)	32 (45.0)		154 (26.4)	8 (12.7)	25 (47.1)	7 (38.8)
Asian or Pacific Islander, non-Hispanic	14 (2.2)	1 (1.4)		10 (1.7)	4 (6.4)	1 (1.9)	0 (—)
All other races^§§	20 (3.1)	2 (2.8)		19 (3.3)	1 (1.6)	1 (1.9)	1 (5.5)
Unknown race and ethnicity	29 (4.5)	5 (7.1)		25 (4.3)	4 (6.4)	3 (5.7)	2 (11.2)
Primary reason for admission^¶¶
Likely related to COVID-19	454 (70.3)	29 (40.8)	<0.001	413 (70.8)	41 (65.0)	19 (35.8)	10 (55.5)
Obstetrics	40 (6.2)	0 (—)		36 (6.2)	4 (6.4)	0 (—)	0 (—)
Inpatient surgery	15 (2.3)	7 (9.8)		13 (2.2)	2 (3.2)	5 (9.4)	2 (11.1)
Psychiatric admission requiring medical care	79 (12.2)	27 (38.1)		72 (12.4)	7 (11.1)	24 (45.3)	3 (16.8)
Trauma	40 (6.2)	4 (5.6)		35 (6.0)	5 (8.0)	3 (5.7)	1 (5.5)
Other reason	16 (2.5)	4 (5.6)		12 (2.1)	4 (6.3)	2 (3.8)	2 (11.1)
Unknown reason	2 (0.3)	0 (—)		2 (0.3)	0 (—)	0 (—)	0 (—)
COVID-19–related symptoms at admission***
Yes	536 (83.0)	53 (74.6)	0.08	487 (83.4)	49 (79.0)	37 (69.8)	16 (88.9)
No	110 (17.0)	18 (25.4)	0.08	97 (16.6)	13 (21.0)	16 (30.2)	2 (11.1)
Hospitalization outcomes
Length of hospital stay, days, median (IQR)	4 (2–7)	3 (1–8)	0.55	4 (2–6.5)	4 (2–8)	3 (2–9)	3 (1–5)
ICU admission^†††	196 (30.3)	11 (15.5)	0.009	184 (31.6)	12 (19.1)	8 (15.1)	3 (16.6)
Invasive mechanical ventilation^†††	42 (6.5)	6 (8.4)	0.54	41 (7.1)	1 (1.6)	5 (9.4)	1 (5.5)
In-hospital death	5 (0.8)	2 (2.8)	0.10	5 (0.9)	0 (—)	2 (3.8)	0 (—)

Abbreviations: COVID-NET = Coronavirus Disease 2019–Associated Hospitalization Surveillance Network; ICU = intensive care unit.
*Fully vaccinated adolescents with COVID-19–associated hospitalizations were defined as those who had received the final dose in their primary series ≥14 days before receiving a positive SARS-CoV-2 test result associated with their hospitalization. Adolescents who received only 1 vaccine dose ≥14 days before the SARS-CoV-2 test date or had received a single dose of vaccine <14 days before the positive SARS-CoV-2 test results were considered partially vaccinated; they were not included in rates and were grouped with unvaccinated adolescents in other analyses. COVID-NET sites, through agreements with state health departments and other partners, collect COVID-19 vaccination information on COVID-19–associated hospitalizations through state-based vaccine registries. When possible, sites collect COVID-19 vaccination status on all persons with COVID-19 cases who are hospitalized, including the number of vaccine doses received, the vaccine product, and dates of vaccination administration.
^†Data are from a weighted sample of hospitalized children and adolescents with completed medical record abstractions. Sample sizes presented are unweighted with weighted percentages.
^§Includes persons admitted to a hospital with an admission date during July 1–December 31, 2021. Maryland contributed data through November 26, 2021. Counties included in COVID-NET surveillance: California (Alameda, Contra Costa, and San Francisco counties); Colorado (Adams, Arapahoe, Denver, Douglas, and Jefferson counties); Connecticut (Middlesex and New Haven counties); Georgia (Clayton, Cobb, DeKalb, Douglas, Fulton, Gwinnett, Newton, and Rockdale counties); Iowa (one county represented); Maryland (Allegany, Anne Arundel, Baltimore, Baltimore City, Calvert, Caroline, Carroll, Cecil, Charles, Dorchester, Frederick, Garrett, Harford, Howard, Kent, Montgomery, Prince George's, Queen Anne's, St. Mary's, Somerset, Talbot, Washington, Wicomico, and Worcester counties); Michigan (Clinton, Eaton, Genesee, Ingham, and Washtenaw counties); Minnesota (Anoka, Carver, Dakota, Hennepin, Ramsey, Scott, and Washington counties); New Mexico (Bernalillo, Chaves, Doña Ana, Grant, Luna, San Juan, and Santa Fe counties); New York (Albany, Columbia, Genesee, Greene, Livingston, Monroe, Montgomery, Ontario, Orleans, Rensselaer, Saratoga, Schenectady, Schoharie, Wayne, and Yates counties); Ohio (Delaware, Fairfield, Franklin, Hocking, Licking, Madison, Morrow, Perry, Pickaway, and Union counties); Oregon (Clackamas, Multnomah, and Washington counties); Tennessee (Cheatham, Davidson, Dickson, Robertson, Rutherford, Sumner, Williamson, and Wilson counties); and Utah (Salt Lake County).
^¶Proportions between vaccinated and unvaccinated adolescents were compared with chi-square tests or Fisher's exact tests (as appropriate), and medians were compared with the Wilcoxon rank sum test; p-values <0.05 were considered statistically significant.
**Data are missing for <5% of observations for all variables.
^††If ethnicity was unknown, non-Hispanic ethnicity was assumed.
^§§Includes non-Hispanic persons reported as other or multiple races.
^¶¶Among sampled patients, COVID-NET collects data on the primary reason for admission to differentiate hospitalizations of patients with laboratory-confirmed SARS-CoV-2 infection who are likely admitted primarily for COVID-19 illness rather than for other reasons. During chart review, if the surveillance officer finds that the chief complaint or history of present illness mentions fever or respiratory illness, COVID-19–like illness, or suspected COVID-19, then the case is categorized as COVID-19–related illness as the primary reason for admission. Reasons for admission that are likely primarily not related to COVID-19 include the following categories: obstetrics/labor and delivery, inpatient surgery or procedures, psychiatric admission requiring acute medical care, trauma, other, or unknown. Reasons categorized as "other" are reviewed by two physicians to determine whether the admission is likely COVID-19 related.
***COVID-19–related symptoms included respiratory symptoms (congestion or runny nose, cough, hemoptysis or bloody sputum, shortness of breath or respiratory distress, sore throat, upper respiratory infection, influenza-like illness, and wheezing) and nonrespiratory symptoms (abdominal pain, altered mental status or confusion, anosmia or decreased smell, chest pain, conjunctivitis, diarrhea, dysgeusia or decreased taste, fatigue, fever or chills, headache, muscle aches or myalgias, nausea or vomiting, rash, and seizures), and among those aged <2 years, included apnea, cyanosis, decreased vocalization or stridor, dehydration, hypothermia, inability to eat or poor feeding, and lethargy. Symptoms are abstracted from the medical chart and might not be complete.
^†††ICU admission and invasive mechanical ventilation are not mutually exclusive categories, and patients could have received both.

Authors and Disclosures

Kristin J. Marks, PhD^1,2, Michael Whitaker, MPH¹, Onika Anglin, MPH^1,3, Jennifer Milucky, MSPH¹, Kadam Patel, MPH^1,3, Huong Pham, MPH¹, Shua J. Chai, MD^4,5, Pam Daily Kirley, MPH⁴, Isaac Armistead, MD⁶, Sarah McLafferty, MPH⁶, James Meek, MPH⁷, Kimberly Yousey-Hindes, MPH⁷, Evan J. Anderson, MD^8–10, Kyle P. Openo, DrPH^8,9, Andy Weigel, MSW¹¹, Justin Henderson, MPH¹², Val Tellez Nunez, MPH¹², Kathryn Como-Sabetti, MPH¹³, Ruth Lynfield, MD¹³, Susan L. Ropp, PhD¹⁴, Chad Smelser, MD¹⁴, Grant R. Barney, MPH¹⁵, Alison Muse, MPH¹⁵, Nancy M. Bennett, MD¹⁶, Sophrena Bushey, MHS¹⁶, Laurie M. Billing, MPH¹⁷, Eli Shiltz, MPH¹⁷, Nasreen Abdullah, MD¹⁸, Melissa Sutton, MD¹⁸, William Schaffner, MD¹⁹, H. Keipp Talbot, MD¹⁹, Ryan Chatelain, MPH²⁰, Andrea George, MPH²⁰, Christopher A. Taylor, PhD¹, Meredith L. McMorrow, MD¹, Cria G. Perrine, PhD¹ and Fiona P. Havers, MD¹, COVID-NET Surveillance Team

¹CDC COVID-19 Emergency Response Team; ²Epidemic Intelligence Service, CDC; ³General Dynamics Information Technology, Atlanta, Georgia; ⁴California Emerging Infections Program, Oakland, California; ⁵Career Epidemiology Field Officer Program, CDC; ⁶Colorado Department of Public Health and Environment; ⁷Connecticut Emerging Infections Program, Yale School of Public Health, New Haven, Connecticut; ⁸Emory University School of Medicine, Atlanta, Georgia; ⁹Georgia Emerging Infections Program, Georgia Department of Public Health; ¹⁰Atlanta Veterans Affairs Medical Center, Atlanta, Georgia; ¹¹Iowa Department of Public Health; ¹²Michigan Department of Health and Human Services; ¹³Minnesota Department of Health; ¹⁴New Mexico Department of Health; ¹⁵New York State Department of Health; ¹⁶University of Rochester School of Medicine and Dentistry, Rochester, New York; ¹⁷Ohio Department of Health; ¹⁸Public Health Division, Oregon Health Authority; ¹⁹Vanderbilt University Medical Center, Nashville, Tennessee; ²⁰Salt Lake County Health Department, Salt Lake City, Utah.

Corresponding author
Kristin J. Marks; KJMarks@cdc.gov.

COVID-NET Surveillance Team
Arthur Reingold, University of California Berkeley Berkeley California; Nisha Alden, Colorado Department of Public Health and Environment; Breanna Kawasaki, Colorado Department of Public Health and Environment; Maria Correa, Connecticut Emerging Infections Program Yale School of Public Health New Haven Connecticut; Carol Lyons, Connecticut Emerging Infections Program Yale School of Public Health New Haven Connecticut; Emily Fawcett, Georgia Emerging Infections Program Georgia Department of Public Health, Atlanta Georgia Veterans Affairs Medical Center Atlanta, Georgia Foundation for Atlanta Veterans Education and Research, Decatur, Georgia; Katelyn Ward, Georgia Emerging Infections Program Georgia Department of Public Health, Atlanta Georgia Division of Infectious Diseases Emory University School of Medicine Atlanta Georgia; Kayla Bilski, Minnesota Department of Health; Erica Bye, Minnesota Department of Health; Emily B. Hancock, University of New Mexico Health Sciences Center New Mexico Emerging Infections Program Albuquerque New Mexico; Murtada Khalifa, CDC Foundation Atlanta Georgia New Mexico Department of Health; Adam Rowe, New York State Department of Health; Nancy Spina, New York State Department of Health; Virginia Cafferky, University of Rochester School of Medicine and Dentistry Rochester New York; Kevin Popham, University of Rochester School of Medicine and Dentistry Rochester New York; Sam Hawkins, Public Health Division Oregon Health Authority; Tiffanie Markus, Vanderbilt University Medical Center Nashville Tennessee; Keegan McCaffrey, Utah Department of Health; Andrea Price, Salt Lake County Health Department Salt Lake City Utah

All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. Evan J. Anderson reports grants from Pfizer, Merck, PaxVax, Micron, Sanofi-Pasteur, Janssen, MedImmune, and GlaxoSmithKline; personal fees from Pfizer, Medscape, Kentucky Bioprocessing, Inc., Sanofi-Pasteur, and Janssen, outside the submitted work; and institutional funding from the National Institutes of Health to conduct clinical trials of Moderna and Janssen COVID-19 vaccines. Laurie M. Billing, Eli Shiltz, Andy Weigel, Justin Henderson, Val Tellez Nunez, and Andrea George report grants from the Council of State and Territorial Epidemiologists during the conduct of the study. Ruth Lynfield reports editorial payments from the American Academy of Pediatrics Red Book (Committee on Infectious Diseases), which were donated to the Minnesota Department of Health. No other potential conflicts of interest were disclosed.