Document text
cdc.gov/coronavirus
Epidemiology of COVID -19-Associated Hospitalizations,
including in Pregnant Persons and Infants
Fiona Havers, MD, MHS, FIDSA
Team Lead, RESP -NET Hospitalization Surveillance Team
Commander, US Public Health Service
Coronavirus and Other Respiratory Viruses Division
National Center for Immunization and Respiratory Diseases
Centers for Disease Control and Prevention
Advisory Committee on Immunization Practices
June 23, 2023
COVID -19-associated hospitalizations
COVID -NET: March 2020 –June 2023
COVID -NET Hospitalizations
▪>250 acute -care hospitals
▪98 counties in 13 states
▪~10% of U.S. population
▪Positive SARS -CoV-2 within 14 days of or
during hospitalization
▪Screening or clinician -driven testing
▪Clinical data is from representative sample
of COVID -NET patients
3
Weekly COVID -19-associated hospitalization rates —COVID -NET, 14 U.S.
States
Rates highest in ≥75 years,
followed by infants <6 months and
those 65 –74 years020406080100120140March 1, 2020 –June 3, 2023
0-<6 months 6 months-4 years 5-11 years 12-17 years
18-49 years 50-64 years 65-74 years ≥ 75 years020406080100120140
7-Jan 7-Feb 7-Mar 7-Apr 7-MayJanuary 1 –June 3, 2023
4
COVID -19-associated hospitalization rates by race and ethnicity* —
COVID -NET, 14 U.S. States, October 2022 –May 2023
* Black, White, American Indian/Alaska Native and Asian/Pacific Islander people
were categorized as non -Hispanic; Hispanic people could be of any race. Cumulative hospitalization rates
remain highest in American
Indian/Alaska Native and Black
persons050100150200250300Hospitalization Rate per 100,000Age adjusted cumulative rates
October 2022 –May 2023
0246810121416Rate per 100,000Age adjusted 3 -week moving average rate
January –May 2023
Hispanic American Indian/Alaska Native Asian/Pacific Islander Black White
5
COVID -19-associated hospitalizations in
pregnant persons
COVID -NET: January 2021 –April 2023
COVID -19-associated hospitalizations among pregnant persons aged 15 –
49 years —COVID -NET, 14 U.S. States, January 2021 –April 2023
Most pregnant people
hospitalized with a positive SARS -
CoV-2 test had no respiratory
symptoms
•363 of 1,651 (21%) had respiratory
symptoms recorded
•Proportion without respiratory
symptoms increased from 73% to 82%
Among symptomatic patients,
the proportion with underlying
medical conditions increasedJanuary –
November 2021
(pre-Omicron)
N (%)December 2021 –
June 2022
(early Omicron)
N (%)July 2022 –April
2023
(later Omicron)
N (%)
Total number 184 99 80
Age group
15-24 years 45 (16) 38 (31) 22 (21)
25-34 years 98 (60) 46 (54) 45 (59)
35-49 years 41 (25) 15 (15) 13 (20)
Any underlying
medical conditions72 (33) 32 (33) 46 (56)
Any pregnancy -
associated
complications*37 (20) 25 (31) 23 (29)Table 1. Characteristics of COVID -19-associated hospitalized pregnant
patients (15 –49 years) with respiratory symptoms
*Pregnancy -associated complications include hypertensive disorders of pregnancy,
gestational diabetes, intrauterine growth restrictions, and pre -eclampsia. Note that
percentages are weighted to account for sampling scheme. 7
January –
November 2021
(pre-Omicron)
N (%)*December 2021
–June 2022
(early Omicron)
N (%)*July 2022 –April
2023
(later Omicron)
N (%) *
Total Number 184 99 80
Interventions
High flow nasal
cannula20 (12) 2 (2) 0 (0)
BIPAP/CPAP 5 (2) 1 (1) 1 (3)
Mechanical
ventilation15 (7) 3 (2) 1 (2)
Vasopressor 26 (15) 3 (2) 3 (6)
Dialysis or RRT 1 (0.5) 1 (1) 0 (0)
Severe outcomes
ICU admission 31 (17) 7 (6) 2 (4)
In-hospital death 0 (0) 1 (1) 0 (0)Interventions and outcomes among pregnant patients with respiratory
symptoms and a positive SARS -CoV-2 test
The p roportion
requiring ICU
admission and
vasopressor support
decreased over time
*Note that percentages are weighted to account for sampling scheme. 8
0102030405060708090100
Unvaccinated Primary
series onlyPrimary
series + ≥ 1
boosterUnvaccinated Primary
series onlyPrimary
series + ≥ 1
boosterUnvaccinated Primary
series onlyPrimary
series + ≥ 1
booster
January-November 2021 (n=1,231) December 2021-June 2022 (n=279) July 2022-January 2023 (n=239)Weighted %
Respiratory symptoms No COVID-19 symptoms recordedVaccination status among pregnant patients hospitalized with
laboratory -confirmed SARS -CoV-2 infection by symptom status, COVID -
NET, January 2021 –April 2023
More asymptomatic
pregnant patients
received boosters
compared with
symptomatic
patients
Most pregnant
patients had not
received booster
doses
9
COVID -19-associated hospitalizations in
infants <6 months
COVID -NET: March 2020 –May 2023
Infants <6 months old had similar COVID -19–associated
hospitalization rates to adults aged 65 –74 years old
Source: COVID -NET: https://www.cdc.gov/coronavirus/2019 -ncov/covid -data/covid -net/purpose -methods.html . Data March 1, 2020 through March 31, 2023. Pre -Delta: March 1, 2020 –
June 19, 2021; Delta: June 20 –December 18, 2021; Omicron BA.1: December 19, 2021 –March 19, 2022; Omicron BA.2: March 20 –June 18, 2022; Omicron BA.5 (J une 19, 2022 –June 3, 2023)Pre-Delta DeltaOmicron
BA.1Omicron
BA.2Omicron BA.5 and later
11020406080100120140160Hospitalization rate per 100,000
0-<6 months 6 months-4 years 5-11 years 12-17 years 65-74 years ≥ 75 years
Hospitalization rates in infants, children and adolescents
aged 6 months through <18 years
Source: COVID -NET: https://www.cdc.gov/coronavirus/2019 -ncov/covid -data/covid -net/purpose -methods.html . Data March 1, 2020 through March 31, 2023. Pre -Delta: March 1, 2020 –June
19, 2021; Delta: June 20 –December 18, 2021; Omicron BA.1: December 19, 2021 –March 19, 2022; Omicron BA.2: March 20 –June 18, 2022; Omicron BA.5 (J une 19, 2022 –May 27, 2023)Pre-Delta DeltaOmicron
BA.1Omicron
BA.2Omicron BA.5 and later
02468101214161820
3/7/2020
4/7/2020
5/7/2020
6/7/2020
7/7/2020
8/7/2020
9/7/2020
10/7/2020
11/7/2020
12/7/2020
1/7/2021
2/7/2021
3/7/2021
4/7/2021
5/7/2021
6/7/2021
7/7/2021
8/7/2021
9/7/2021
10/7/2021
11/7/2021
12/7/2021
1/7/2022
2/7/2022
3/7/2022
4/7/2022
5/7/2022
6/7/2022
7/7/2022
8/7/2022
9/7/2022
10/7/2022
11/7/2022
12/7/2022
1/7/2023
2/7/2023
3/7/2023
4/7/2023
5/7/2023Rate per 100,000
6 months <2 years 2-4 years 5-11 years 12-17 years
12
On average, 15% of hospitalized infants <6 months with
COVID -19 were identified during their birth hospitalization*
*Birth hospitalization was defined as admission date within 1 day of birth. Source: COVID -NET: https://www.cdc.gov/coronavirus/2019 -ncov/covid -data/covid -net/purpose -methods.html . Data March 1, 2020
through March 31, 2023. Pre -Delta: March 1, 2020 –June 19, 2021; Delta: June 20 –December 18, 2021; Omicron BA.1: December 19, 2021 –March 19, 2022; Omicron BA.2: March 20 –June 18, 2022; Omicron
BA.5 (June 19, 2022 –March 31, 2023) . 18 16 1620
11
0%10%20%30%40%50%60%70%80%90%100%
Pre-Delta Delta Omicron BA.1 Omicron BA.2 Omicron BA.5 and later
Birth hospitalization Separate hospitalization
13
95% of infants <6 months old with a separate hospitalization
had COVID -19 symptoms during the Omicron BA.5 period
Source: COVID -NET: https://www.cdc.gov/coronavirus/2019 -ncov/covid -data/covid -net/purpose -methods.html . Data March 1, 2020 through March 31, 2023. Pre -Delta: March 1, 2020 –June 19,
2021; Delta: June 20 –December 18, 2021; Omicron BA.1: December 19, 2021 –March 19, 2022; Omicron BA.2: March 20 –June 18, 2022; Omicron BA.5 (J une 19, 2022 –March 31, 2023)93 94 94 97 95
0%10%20%30%40%50%60%70%80%90%100%
Pre-Delta Delta Omicron BA.1 Omicron BA.2 Omicron BA.5 and
later
Symptoms No symptoms
14
1 in 5 infants < 6 months old with COVID -19 were admitted to
the ICU (excluding birth hospitalizations)
Source: COVID -NET: https://www.cdc.gov/coronavirus/2019 -ncov/covid -data/covid -net/purpose -methods.html . Data March 1, 2020 through March 31, 2023. Pre -Delta: March 1, 2020 –June
19, 2021; Delta: June 20 –December 18, 2021; Omicron BA.1: December 19, 2021 –March 19, 2022; Omicron BA.2: March 20 –June 18, 2022; Omicron BA.5 (J une 19, 2022 –March 31, 2023)19%
5%
2% 2%
0.3%18%
14%
4%5%
0.0%24%
15%
8%
3%
1%21%
14%
5%4%
2%20%
19%
3%6%
0%
0%5%10%15%20%25%30%
ICU admission High flow nasal cannula Invasive mechanical
ventilationBiPAP or CPAP use In-hospital deathWEIGHTED % OF COVID -19-ASSOCIATED HOSPITALIZATIONSPre-delta
Delta
Omicron BA.1
Omicron BA.2
Omicron BA.5 and later
15
•General : Hospitalization rates decreased in all age groups
•The age distribution of persons hospitalized with COVID -19 has shifted such that the highest
rates are in adults aged ≥75 years followed by those 65 -74 years and infants ages <6 months
•Pregnant persons:
•Most pregnant persons hospitalized with a positive SARS -CoV-2 test had no symptoms
recorded at admission and were likely identified through screening on admission
•Among those with respiratory symptoms, the proportion with underlying medical conditions
has increased and the proportion with severe outcomes has decreased
•Most hospitalized pregnant persons with a positive SARS -CoV-2 test, regardless of symptoms
or reason for testing, were not up to date with vaccinations
•Infants <6 months : Hospitalization rates increased in the Omicron period
•Most hospitalized with COVID -19-like symptoms
•Excluding birth hospitalizations, 20% admitted to the ICU since June 2022Trends in COVID -19-associated hospitalizations –COVID -NET, March 2020
–May 2023
16
Acknowledgments
Coronaviruses and Other Respiratory
Viruses Division (CORVD):
RESP -NET Team (COVID -NET/RSV -NET):
•Michael Whitaker
•Kadam Patel
•Christopher Taylor
•Huong Pham
•Onika Anglin
•Jenny Milucky
•Bhoomija Chatwani
•Michael Melgar
•Monica Patton
Many others in CORVD….▪State, Local, and Territorial
health Department partners
▪RESP -NET partners
Thank you.
Centers for Disease Control and Prevention
COVID -19 in pregnant people
Romeo Galang, MD MPH
Emergency Preparedness and Response Team
Field Support Branch
Division of Reproductive Health
National Center for Chronic Disease Prevention and Health Promotion
Disease burden and risks to
maternal and infant health
COVID -19 in Pregnant People
▪COVID -19 during pregnancy is associated with more severe maternal
health outcomes
▪COVID -19 during pregnancy is associated with adverse pregnancy
outcomes (e.g., preterm birth, stillbirth)
▪Adverse maternal, fetal, and infant outcomes differed according to the
circulating variant
Reported COVID -19 cases overall and among pregnant people in the US
(National COVID -19 Case Surveillance Data; Jan 22, 2020 –May 3, 2023)
Total among
pregnant people:
226,263 cases
738 ICU admissions
329 Deaths
050001000015000200002500030000
Overall Cases
Cases among
pregnant
peoplePre-Delta Delta Omicron
Among people with COVID -19, pregnancy increased the risk for ICU
admission and invasive ventilation
(Living Systematic Review with data from 1 Dec 2019 -27 Apr 2021)
Outcomes # Studies# with event/# in group (%)
Odds ratio (95% CI)
Pregnant with COVID -19Non -pregnant with
COVID -19
All cause mortality 11 242/122 222 (0.2) 5252/2 138 726 (0.2) 1.48 (0.62 to 3.49)
ICU admission 10 912/118 403 (0.8) 11 513/1 908 957 (0.6) 2.61 (1.84 to 3.71)
Invasive ventilation 8 310/116 458 (0.3) 3607/1 772 716 (0.2) 2.41 (2.13 to 2.71)
ECMO 5 19/30 694 (0.1) 122/432 623 (0.0) 3.71 (0.71 to 19.41)
ARDS 4 22/197 (11.2) 45/418 (10.8) 1.19 (0.24 to 5.95)
Major organ failure 4 5/197 (2.5) 28/418 (6.7) 0.39 (0.15 to 1.04)
Allotey, J et al. Clinical manifestations, risk factors, and maternal and perinatal outcomes of coronavirus disease 2019 in pregnancy: living systematic review and meta -
analysis. BMJ . 2020. Final version 7 -May 2022 https://doi.org/10.1136/bmj.m3320ECMO: extracorporeal membrane oxygenation; ARDS: Acute respiratory distress syndrome
Among pregnant people , COVID -19 increased the risk for adverse
maternal, fetal, and infant outcomes
(Living Systematic Review with data from 1 Dec 2019 -27 Apr 2021)
Outcomes # Studies# with event/# in group (%)
Odds ratio (95% CI)Pregnant with COVID -19Pregnant without
COVID -19
Maternal outcomes:
All cause mortality 21 47/11 362 (0.4) 37/411 126 (0.0) 6.09 (1.82 to 20.38)
ICU admission 21 447/12 957 (3.4) 1962/459 359 (0.4) 5.41 (3.59 to 8.14)
Preterm birth <37 weeks 48 1306/12 076 (10.8) 26 068/436 964 (6.0) 1.57 (1.36 to 1.81)
Perinatal outcomes:
Stillbirth 25 76/9338 (0.8) 1397/414 139 (0.3) 1.81 (1.38 to 2.37)
Neonatal death 21 16/3153 (0.5) 28/9 263 (0.3) 2.35 (1.16 to 4.76)
Admission to neonatal unit 29 687/4072 (16.9) 6968/193 124 (3.6) 2.18 (1.46 to 3.26)
Fetal distress 6 131/1073 (12.2) 246/3933 (6.3) 2.22 (1.45 to 3.41)
Allotey, J et al. Clinical manifestations, risk factors, and maternal and perinatal outcomes of coronavirus disease 2019 in pregnancy: living systematic review and meta -
analysis. BMJ . 2020. Final version 7 -May 2022 https://doi.org/10.1136/bmj.m3320
Pregnancy -related mortality increased rapidly in 2021 (pre -Omicron),
consistent with rising rates of COVID -19 associated mortality
Thoma , M. E., & Declercq , E. R. (2023). Changes in Pregnancy -Related Mortality Associated With the Coronavirus Disease 2019 (COVID -19) Pandemic in the U nited States. Obstetrics and gynecology ,141(5),
911–917. https://doi.org/10.1097/AOG.0000000000005182
Have risks evolved by COVID -19 variant?
Figure 1. Maternal deaths and maternal deaths mentioning
COVID -19, by count, US 2020 -2022
Pre-delta Delta Omicron
Note: Data for 2020 -2021 are final and data for 2022 -2023. Death counts between 1 -9 are suppressed in accordance with NCHS conf identiality standards. Weeks with COVID -19 death counts 1 -9 are noted on the figure with
black and grey diagonal lines.
Source: CDC, National Center for Health Statistics. National Vital Statistics System, Provisional Mortality on CDC WONDER Onl ineDatabase. Accessed at http://wonder.cdc.gov/mcd -icd10 -provisional.html 020406080100120140160180200Number of Deaths
Date of DeathMaternal Deaths without COVID-19 Maternal Deaths with COVID-19 Counts 1-9
Updated Premier: Pregnant Person Complications Associated With a
Documented COVID -19 Diagnosis at Delivery Hospitalization —
United States, Pre -delta, Delta, and Omicron
Ko et al., 2021 (n = 489471)
June 2021 -December 2021 (n=505108 )
2022 (n = 782503)
*Data from Delta and
Omicron periods are
unpublished
Updated Premier: Pregnant Person Complications Associated With a
Documented COVID -19 Diagnosis at Delivery Hospitalization —
United States, Pre -delta, Delta, and Omicron
Ko et al., 2021 (n = 489471)
June 2021 -December 2021 (n=505108 )
2022 (n = 782503)Although less than Delta,
risks remain elevated
during Omicron
*Data from Delta and
Omicron periods are
unpublished
Updated Premier: Pregnant Person Complications Associated With a
Documented COVID -19 Diagnosis at Delivery Hospitalization —
United States, Pre -delta, Delta, and Omicron
*Data from Delta and
Omicron periods are
unpublished
Ko et al., 2021 (n = 489471)
June 2021 -December 2021 (n=505108 )
2022 (n = 782503)
Updated Premier: Pregnant Person Complications Associated With a
Documented COVID -19 Diagnosis at Delivery Hospitalization —
United States, Pre -delta, Delta, and Omicron
Ko et al., 2021 (n = 489471)
June 2021 -December 2021 (n=505108 )
2022 (n = 782503)
*Data from Delta and
Omicron periods are
unpublishedSimilar pattern: Although less than Delta,
increased risks persisted during Omicron
Updated Premier: Pregnant Person Complications Associated With a
Documented COVID -19 Diagnosis at Delivery Hospitalization —
United States, Pre -delta, Delta, and Omicron
Ko et al., 2021 (n = 489471)
June 2021 -December 2021 (n=505108 )
2022 (n = 782503)
*Data from Delta and
Omicron periods are
unpublished
Similar pattern: Although less than Delta,
increased risks persisted during Omicron
Adverse Pregnancy Outcomes Associated With a Documented COVID -
19 Diagnosis at Delivery Hospitalization —United States,
Pre-delta, Delta, and Omicron Periods, Premier
Ko et al., 2021 (n = 489471)
June 2021 -December 2021 (n=505108)
2022 (n = 782503)
*Data from Delta and
Omicron periods are
unpublished
Adverse Pregnancy Outcomes Associated With a Documented COVID -
19 Diagnosis at Delivery Hospitalization —United States,
Pre-delta, Delta, and Omicron Periods, Premier
Ko et al., 2021 (n = 489471)
June 2021 -December 2021 (n=509265)
2022 (n = 765425)
*Data from Delta and
Omicron periods are
unpublished•Although less than Delta, risks
for adverse pregnancy
outcomes and preterm delivery
remain elevated during Omicron
•Risk for stillbirth not
significantly elevated during
Omicron
Trends (%) in pregnancy outcomes by maternal COVID -19 status:
14 states and the District of Columbia (July 2020 -December 2022)
pre-Delta
July 2020 -June 2021Delta
July 2021 -December 2021Omicron
January 2022 -December 2022
COVID -191No COVID -19 COVID -191No COVID -19 COVID -191No COVID -19
ICU admission 0.6 0.1 1.2 0.2 0.2 0.2
NICU admission 10.3 8.7 10.9 8.5 9.0 8.7
Total preterm211.9 9.9 13.0 10.1 10.3 10.1
Early preterm 3.2 2.6 3.8 2.7 2.4 2.7
Late preterm 8.8 7.2 9.2 7.4 7.9 7.4
Total low birthweight38.8 7.9 9.8 8.1 7.9 8.2
Very low birthweight41.5 1.3 1.6 1.3 1.1 1.3
1 Confirmed or presumed COVID -19 during pregnancy. Confirmed cases only are included for California, Maryland, Ohio, North Dakota, and Tennessee.
2Gestational age in completed weeks; based on the obstetric estimate of gestation.
3 Less than 2,500 grams
4 Less than 1,500 grams
NOTES: Reporting area includes Alabama, Alaska, Arkansas, California, District of Columbia, Idaho, Maine, Maryland, New Hamps hire, North Dakota, Ohio, Oklahoma, Oregon, Tennessee, and West Virginia. District of Columbia did not report for October -December
2022.
SOURCE: National Center for Health Statistics, National Vital Statistics System, Natality.
https://www.cdc.gov/nchs/data/health_policy/trends -in-outcomes.pdf
Summary
▪Incidence of COVID -19 among pregnant people mirrors that of the general
population
▪Pregnancy remains a risk factor for severe maternal disease and adverse
pregnancy outcomes, even with new variants
▪Some maternal, fetal, and infant risks were lower with Omicron; cannot
disentangle the impact of prior infection/vaccination
Conclusion
COVID -19 vaccination improves outcomes for pregnant
people, their pregnancies and their infants; therefore
vaccination should continue to be recommended for maternal
and fetal benefit
For more information, contact CDC
1-800-CDC-INFO (232 -4636)
TTY: 1 -888-232-6348 www.cdc.gov
The findings and conclusions in this report are those of the authors and do not necessarily represent the
official position of the Centers for Disease Control and Prevention.
National Center for Immunization and Respiratory Diseases
Sascha Ellington
Katherine Fleming -Dutra
Sara Oliver
Regina Simeone
National Center for Health Statistics
Donna Hoyert
Joyce Martin
Michelle Osterman
Claudia ValenzuelaAcknowledgements
National Center on Birth Defects and Developmental Disorders
Jeffrey Carlson
Amanda Cohn
Dana Meaney -Delman
Suzanne Gilboa
Kara Polen
Emily Reeves
Van Tong
Kate Woodworth
Centers for Disease Control and Prevention
National Center for Immunization and Respiratory Diseases
Centers for Disease Control and Prevention
National Center for Immunization and Respiratory Diseases
Centers for Disease Control and Prevention
National Center for Immunization and Respiratory Diseases
Centers for Disease Control and Prevention
National Center for Immunization and Respiratory Diseases
Photographs and images included in this presentation are licensed solely for CDC/NCIRD online and presentation use. No rights are implied or extended for use in printing or any use by other CDC CIOs or any external audiences.COVID -19 vaccine effectiveness updates
23 June 2023
Ruth Link -Gelles, PhD, MPH
LCDR, US Public Health Service
COVID -19 Vaccine Effectiveness Program Lead
Centers for Disease Control and Prevention
Coverage / Age (years) <22–45–1112–1718–2424–4950–64>65
At least one dos e† 8.9 10.9 40.0 72.2 82.3 85.5 95.0 95.0
At least one bivalent dose 0.6 0.6 4.8 7.8 7.4 12.1 21.7 43.3
Unvaccinated 91.1 89.1 60.0 27.8 17.7 14.5 —†—†U.S. COVID -19 Vaccination Coverage (%) of Total Population by
Age Group —May 10, 2023
†Note: Coverage is capped at 95%
Source: https://covid.cdc.gov/covid -data -tracker/#vaccination -demographics -trends Updated June 1, 2023 39
▪Bivalent VE, by outcome and Omicron subvariant in adults
▪VE in special populations:
–Monovalent and bivalent VE in pregnant people
–Bivalent people with immunocompromising conditionsOrganization of vaccine effectiveness (VE) data
40
Monovalent and bivalent VE, against
hospitalization and critical illness by Omicron
subvariant in adults ≥18 years, VISION Network
VISION Multi -State Network of Electronic Health Records
▪Variant periods designated for analysis
based on time when novel sublineage
became predominant (>50%) at study
site
▪VE a djusted for age, sex, race and
ethnicity, geographic region, and
calendar time
▪Vaccination documented by electronic
health records and state and city
registries▪Cases : COVID -like illness (CLI) with positive PCR for
SARS -CoV-2 within 14 days before or 72 hours after the
admission or encounter
▪Controls : CLI with negative PCR for SARS -CoV-2
42
VISION: Absolute VE of monovalent and bivalent booster doses against
hospitalization and critical illness among immuno competent adults aged
≥18 years –September 2022 –May 2023
Critical illness defined as admission to intensive care unit or death; case -patients were persons admitted to ICU or who experie nced death associated with COVID -19, and control patients were persons hospitalized without COVID -19.
VE estimates adjusted for age, sex, race and ethnicity, geographic region, and calendar time. Updated from: Link -Gelles et al., MMWR, https://www.cdc.gov/mmwr/volumes/72/wr/mm7221a3.htm43mRNA Dosage PatternTotal
testsSARS -CoV-2-
test-positive,
N (%)Median interval
since last dose,
days (IQR)Adjusted VE
(95% CI)
Hospitalization
Unvaccinated (ref) 16,219 1,835 (11) -- Ref
Monovalent doses only 38,843 4,086 (11) 381 (275 -513) 21 (16 -26)
Bivalent booster, 7 -59 days earlier 4,894 329 (7) 35 (21 -47) 62 (57 -67)
Bivalent booster, 60 -119 days earlier 5,283 491 (9) 87 (73 -103) 47 (41 -53)
Bivalent booster, 120 -179 days earlier 3,756 346 (9) 146 (132 -161) 24 (12 -33)
Critical illness
Unvaccinated (ref) 14,762 378 (3) -- Ref
Monovalent doses only 35,415 658 (2) 380 (275 -514) 31 (21 -40)
Bivalent booster, 7 -59 days earlier 4,614 49 (1) 34 (21 -47) 69 (58 -77)
Bivalent booster, 60 -119 days earlier 4,880 88 (2) 87 (73 -103) 45 (29 -58)
Bivalent booster, 120 -179 days earlier 3,445 35 (1) 146 (132 -161) 52 (30 -67)
-20 0 20 40 60 80 100
Vaccine Effectiveness (%)
VISION: Absolute VE of monovalent and bivalent booster doses against
hospitalization and critical illness among immuno competent adults aged ≥18 years,
during BA.4/5 predominance –September 2022 –January 2023
CDC unpublished data. VE estimates adjusted for age, sex, race and ethnicity, geographic region, and calendar time.
Variant predominance based on regional circulation: https://covid.cdc.gov/covid -data -tracker/#variant -proportions44mRNA Dosage PatternTotal
testsSARS -CoV-2-
test-positive,
N (%)Median interval
since last dose,
days (IQR)Adjusted VE
(95% CI)
Hospitalization
Unvaccinated (ref) 11,240 1,426 (13) -- Ref
Monovalent doses only 27,564 3,106 (11) 349 (238 -460) 25 (19 -30)
Bivalent booster, 7 -89 days earlier 6,723 524 (8) 47 (28 -67) 61 (56 -65)
Bivalent booster, ≥90 days earlier 1,511 163 (11) 105 (96 -115) 40 (28 -50)
Critical illness
Unvaccinated (ref) 10,110 296 (3) -- Ref
Monovalent doses only 24,976 518 (2) 347 (236 -460) 33 (21 -42)
Bivalent booster, 7 -89 days earlier 6,199 91 (1) 47 (28 -66) 61 (50 -70)
Bivalent booster, ≥90 days earlier 1,348 25 (2) 105 (96 -115) 49 (21 -67)
-20 0 20 40 60 80 100
Vaccine Effectiveness (%)
VISION: Absolute VE of monovalent and bivalent booster doses against
hospitalization and critical illness among immuno competent adults aged
≥18 years, during XBB predominance –January –May 2023
CDC unpublished data. VE estimates adjusted for age, sex, race and ethnicity, geographic region, and calendar time.
* These interim estimates are imprecise, which might be because of a relatively small number of persons in each level of vacc ination or case status. This imprecision indicates
the actual VE may be substantially different from the point estimate shown, and estimates should therefore be interpreted wit h caution. Additional data accrual should increase
precision and allow appropriate interpretation.
Variant predominance based on regional circulation: https://covid.cdc.gov/covid -data -tracker/#variant -proportions45mRNA Dosage PatternTotal
testsSARS -CoV-2-
test-positive,
N (%)Median interval
since last dose,
days (IQR)Adjusted VE
(95% CI)
Hospitalization
Unvaccinated (ref) 4,979 409 (8) -- Ref
Monovalent doses only 11,279 980 (9) 469 (375 -605) 9 (-4 to 20)
Bivalent booster, 7 -89 days earlier 1,045 60 (6) 65 (43 -79) 51 (35 to 63)
Bivalent booster, 90 -179 days earlier 4,654 419 (9) 139 (119 -157) 20 (7 to 32)
Critical illness
Unvaccinated (ref) 4,652 82 (2) -- Ref
Monovalent doses only 10,439 140 (1) 469 (375 -602) 28 (3 to 46)
Bivalent booster, 7 -89 days earlier 994 9 (1) 65 (43 -78) 58 (15 to 79)*
Bivalent booster, 90 -179 days earlier 4282 47 (1) 139 (119 -157) 48 (23 to 65)
-20 0 20 40 60 80 100
Vaccine Effectiveness (%)
Monovalent and bivalent VE against
hospitalization among adults aged ≥18 years ,
IVY Network
IVY Network —25 hospitals, 20 U.S. States
▪Design : Prospective, case -control
▪Population : Adults aged ≥18 years hospitalized with
Acute respiratory illness (ARI)*
–Cases: ARI and test positive for SARS -CoV-2 by NAAT or
antigen test within 10 days of illness
–Controls: ARI and test negative for SARS -CoV-2 and influenza
by NAAT within 10 days of illness
▪Vaccination data: Electronic medical records (EMR),
state and city registries, and self -report
▪Specimens: Upper respiratory specimens obtained
for central RT -qPCR testing and sequencing
*ARI is defined as presence of any one of the following: fever, cough, shortness of breath, chest imaging consistent with pne umo nia, hypoxemia
IVY Network: Absolute VE against COVID -19 hospitalization
among immuno competent adults aged ≥18 years —September 8,
2022 –May 29, 2023
Total Cases and
Controls Cases (%)Median time
since last dose,
days (IQR)Adjusted VE*,
% (95% CI)
Absolute VE
Unvaccinated (Ref) 1286 537 (42) -- Ref
Monovalent doses only 3511 1460 (42) 393 (282 –517) 16 (3 to 26)
Bivalent booster dose, 7 –59 days earlier 374 100 (27) 36 (21–49) 54 (39 to 65)
Bivalent booster dose, 60 –119 days earlier 443 160 (36) 89 (73–103) 34 (15 to 50)
Bivalent booster dose, 120 –179 days earlier 366 157 (43) 145 (133 –159) 6 (-27 to 30)*
-40 -20 0 20 40 60 80 100
Vaccine Effectiveness (%)
* These interim estimates are imprecise, which might be because of a relatively small number of persons in each level of vacc ination or case status. This imprecision indicates the actual VE may be substantially different
from the point estimate shown, and estimates should therefore be interpreted with caution. Additional data accrual should inc rease precision and allow appropriate interpretation.
VE adjustments: Age, sex, race, ethnicity, admission date (biweekly), and HHS region
IVY Network: Absolute VE against COVID -19 hospitalization
among immuno competent adults aged ≥18 years by lineage
period —September 8, 2022 –May 24, 2023
Total Cases and
Controls Cases (%)Median time
since last dose,
days (IQR)Adjusted VE*,
% (95% CI)
BA.4/5 (September 8 –November 13, 2022)
Unvaccinated (Ref) 313 138 (44) -- Ref
Monovalent doses only 1003 398 (40) 304 (188 –386) 30 (8–47)
Bivalent booster dose, 7 –59 days earlier 83 26 (31) 25 (13–40) 59 (21–78)*
BQ.1 (November 14, 2022 –January 22, 2023)
Unvaccinated (Ref) 458 190 (41) -- Ref
Monovalent doses only 1262 504 (40) 386 (297 –518) 17 (-5 to 34)
Bivalent booster dose, 7 –59 days earlier 226 52 (23) 40 (25–52) 63 (44–75)
Bivalent booster dose, 60 –119 days earlier 225 68 (30) 83 (69–95) 49 (24–66)
XBB (January 23 –May 24, 2023)
Unvaccinated (Ref) 514 209 (41) -- Ref
Monovalent doses only 1246 558 (45) 464 (378 –590) -8 (-34 to 13)
Bivalent booster dose, 7 –89 days earlier 155 56 (36) 64 (46–78) 29 (-8 to 53)*
Bivalent booster dose, 90 –179 days earlier 478 208 (44) 137 (118 –154) -8 (-44 to 19)*
* These interim estimates are imprecise, which might be because of a relatively small number of persons in each level of vacc ination or case status. This imprecision indicates the actual VE may be
substantially different from the point estimate shown, and estimates should therefore be interpreted with caution. Additional data accrual should increase precision and allow appropriate interpretation.
VE adjustments: Age, sex, race, ethnicity, admission date (biweekly), and HHS region-55 -35 -15 5 25 45 65 85
Vaccine Effectiveness (%)
VE in special populations:
pregnant people
VISION Multi -State Network of Electronic Health Records
▪Cases : COVID -like illness (CLI) with positive PCR for
SARS -CoV-2 within 14 days before or 72 hours after the
encounter
▪Controls : CLI with negative PCR for SARS -CoV-2
51▪Among pregnant people 18 -45 years at time of
emergency department/urgent care encounter
▪VE adjusted for age, ethnicity, race, underlying
medical conditions, gestational age at
encounter, site, Medicaid status, day of
encounter, site facility urbanicity
▪Vaccination documented by electronic health
records and state and city registries
▪Separate results for COVID -19 vaccine
monovalent doses received prior to pregnancy
and bivalent doses received during pregnancy
due to timing of bivalent authorization/analysis
(Sept 2022 -May 2023)
VISION: Absolute VE of COVID -19 monovalent doses received prior to
pregnancy against ED/UC encounters among immuno competent pregnant
persons aged 18 -45 years –June 2022 –May 2023*
Adjusted for: Age, ethnicity, race, underlying medical conditions, gestational age at encounter, site, Medicaid status, day o f encounter, site facility urbanicity
*Unpublished CDC data.52Vaccine Dosage PatternTotal
testsSARS -CoV-2-
test-positive,
N (%)Median interval
since last dose,
days (IQR)Adjusted VE
(95% CI)
Absolute VE
Unvaccinated (ref) 2238 317 (14) -- Ref
Monovalent received:
<6 months before pregnancy 833 108 (13) 270 (216, 326) 27 (6, 44)
≥6 months before pregnancy 1986 264 (13) 454 (375, 544) 5 (-15, 22)
-20 0 20 40 60 80 100
Vaccine Effectiveness (%)
VISION: Absolute VE of COVID -19 bivalent doses received during pregnancy
against ED/UC encounters among immuno competent pregnant persons aged
18-45 years –September 2022 –May 2023*
Adjusted for: Age, ethnicity, race, underlying medical conditions, gestational age at encounter, site, Medicaid status, day o f encounter, site facility urbanicity
*Unpublished CDC data
**Doses received during pregnancy for bivalent group
***These interim estimates are imprecise, which might be because of a relatively small number of persons in each level of vac cination or case status. This imprecision
indicates the actual VE may be substantially different from the point estimate shown, and estimates should therefore be inter preted with caution. Additional data accrual
should increase precision and allow appropriate interpretation.53Vaccine Dosage PatternTotal
testsSARS -CoV-2-
test-positive,
N (%)Median
interval
since last dose,
days (IQR)Adjusted VE
(95% CI)
Absolute VE
Unvaccinated (ref) 1701 196 (12) -- Ref
Bivalent dose** 191 10 (5) 56 (29, 97) 61 (22, 81)***
0 20 40 60 80 100
Vaccine Effectiveness (%)
▪Cases infants : hospitalized with COVID -19 as the
primary reason for admission and with a positive
SARS -CoV-2 RT -PCR or antigen test result
▪Control infants : hospitalized with or without
COVID -19 symptoms and negative SARS -CoV-2
RT-PCR or antigen test result
–Matched to case -infants by site; hospitalized within 4
weeks of case -infant admission▪Case -control study to assess effectiveness of
maternal vaccination for COVID -19 in infants < 6
months of age
▪25 pediatric hospitals across 20 states
▪Infants admitted between March 9, 2022, and
May 9, 2023
▪Baseline demographic and clinical characteristics
obtained via parent interview
▪Maternal vaccination status verified using state
vaccination registries, electronic medical records,
or other sourcesOvercoming COVID -19 network
54
Overcoming COVID -19: Effectiveness of maternal vaccination in prevention
of hospitalization among infants –March 9, 2022 –May 9, 2023
CDC unpublished data. VE estimates adjusted for infant age, sex, race and ethnicity, census region, and month and year of hos pitalization. 55Vaccination during pregnancy* TotalCase infants,
N (%)Median interval
since last maternal
dose, days (IQR)Infant median age at
hospitalization, days
(IQR)Adjusted VE
(95% CI)Effectiveness of Maternal Vaccination against
Infant Covid -19 Hospitalization % (95% CI)†
Infants <3 months of age at hospitalization
Unvaccinated (ref) 310 174 (56) NA 44 (27 to 63) Ref
Vaccinated 101 43 (43) 222 (152 to 271) 41 (23 to 66) 56 (24 to 75)*
Infants < 6 months of age at hospitalization
Unvaccinated (ref) 498 281 (56) NA 68 (37 to 125) Ref
Vaccinated 163 78 (48) 236 (190 to 302) 74 (33 to 132) 38 (7 to 59)*
0 20 40 60 80 100
Vaccine Effectiveness (%)
*Last mRNA or viral vector vaccine dose received between the beginning of pregnancy and 14 days before delivery. 14 people re ceived a bivalent mRNA vaccine.
†These estimates are imprecise, which might be because of a relatively small number of persons in each level of vaccination o r case status. This imprecision indicates the actual VE may be
substantially different from the point estimate shown, and estimates should therefore be interpreted with caution. Additional data accrual should increase precision and allow appropriate
interpretation.
Bivalent VE in special populations:
people with immunocompromising conditions
VISION: Absolute VE of monovalent and bivalent booster doses against
hospitalization and critical illness among immuno compromised adults
aged ≥18 years –September 2022 –May 2023
* These interim estimates are imprecise, which might be because of a relatively small number of persons in each level of vacc ination or case status. This imprecision indicates
the actual VE may be substantially different from the point estimate shown, and estimates should therefore be interpreted wit h caution. Additional data accrual should increase
precision and allow appropriate interpretation.
Critical illness defined as admission to intensive care unit or death; case -patients were persons admitted to an ICU or who expe rienced death associated with COVID -19, and control patients were persons hospitalized
without COVID -19. VE estimates adjusted for age, sex, race and ethnicity, geographic region, and calendar time. Updated from: Li nk-Gelles et al., MMWR, https://www.cdc.gov/mmwr/volumes/72/wr/mm7221a3.htm57mRNA Dosage PatternTotal
testsSARS -CoV-2-
test-positive,
N (%)Median interval
since last dose,
days (IQR)Adjusted VE
(95% CI)
Hospitalization
Unvaccinated (ref) 3,240 322 (10) -- Ref
Monovalent doses only 11,623 1,169 (10) 359 (242 -481) 3 (-12-16)
Bivalent booster, 7 -59 days earlier 1,627 144 (9) 33 (19 -46) 27 (9 -41)
Bivalent booster, 60 -119 days earlier 1,862 144 (8) 88 (74 -104) 39 (24 -51)
Bivalent booster, 120 -179 days earlier 1,448 118 (8) 146 (133 -161) 11 (-13-31)
Critical illness
Unvaccinated (ref) 3,006 88 (3) -- Ref
Monovalent doses only 10,725 271 (3) 358 (241 -481) 16 (-10-35)
Bivalent booster, 7 -59 days earlier 1,515 32 (2) 33 (19 -46) 41 (8 -62)*
Bivalent booster, 60 -119 days earlier 1,755 37 (2) 88 (74 -104) 43 (13 -62)
Bivalent booster, 120 -179 days earlier 1,348 18 (1) 146 (133 -162) 51 (15 -72)*
-20 0 20 40 60 80 100
Vaccine Effectiveness (%)
Summary and conclusions
▪For estimates of absolute vaccine effectiveness, if unvaccinated are meaningfully
different from vaccinated individuals (e.g., by COVID -19 risk factors), estimates may
be biased.
–For estimates of relative vaccine effectiveness, residual protection from prior doses is an important
consideration for interpretation.
▪Information on prior infection is limited, although we know rates of prior infection in
the U.S. population are high and vary by age.
▪VE against COVID -19-associated hospitalization may underestimate protection against
more severe COVID -19 disease.
▪Lack of statistical power to estimate VE for maternal vaccination by timing of doses
during pregnancy; could not separate monovalent and bivalent doses for protection
against infant hospitalizationLimitations of VE against severe disease
59
▪Bivalent boosters are helping provide additional protection against hospitalization, though evidence of waning
▪For most people who received monovalent doses and are eligible for a bivalent booster, more than a year has
elapsed since their last monovalent dose. Because of waning, they may have limited remaining protection against
hospitalization.
▪Effectiveness against the most critical illness (ICU admission and death) more sustained compared to less severe
illness
▪VE during XBB predominance may wane more quickly against hospitalization compared to early variant
predominant periods
▪Vaccination during pregnancy provides protection against hospitalization for infants <6 months; protection may be
highest in the first 3 months
▪CDC will continue ongoing monitoring of VE, including for all outcomes of interest and for all authorized COVID -19
vaccines in the U.S. with a focus on assessing new policy recommendations and VE in populations at higher risk of
severe COVID -19Conclusions: updates to VE of bivalent COVID -19 boosters
60
CDC COVID -19 Vaccine Effectiveness and
Policy Team
▪Amadea Britton
▪Allison Ciesla
▪Monica Godfrey
▪Eric Griggs
▪Katherine Fleming -Dutra
▪Dani Moulia
▪Morgan Najdowski
▪Erica OkwuaziVE platforms teams, including:
▪Sarah Ball
▪Angela Campbell
▪Jennifer DeCuir
▪Monica Dickerson
▪Margaret Dunne
▪Kiara Everett
▪Shikha Garg
▪Victoria Lazariu
▪Patrick Mitchell
▪Palak Patel
And many more!!!Acknowledgements
61▪Caitlin Ray
▪Sarah Reese
▪Elizabeth Rowley
▪Regina Simeone
▪Zach Smith
▪Diya Surie
▪Mark Tenforde
▪Zack Weber
▪Laura Zambrano▪Sara Oliver
▪Josephine Mac
▪Amanda Payne
▪Lauren Roper
▪Laura Steinhardt
▪Evelyn Twentyman
▪Megan Wallace
▪Ryan Wiegand
For more information, contact CDC
1-800-CDC-INFO (232 -4636)
TTY: 1 -888-232-6348 www.cdc.gov
The findings and conclusions in this report are those of the authors and do not necessarily represent the
official position of the Centers for Disease Control and Prevention.Questions?