Document text
Updates to COVID -19 Vaccine Effectiveness
COVID -19 Session
Coronavirus and Other Respiratory Viruses Division
June 25, 2025National Center for Immunization and Respiratory Diseases
2•Vaccine effectiveness methods & context
•Estimates of COVID -19 Vaccine Effectiveness in Children
•Estimates of COVID -19 Vaccine Effectiveness in Adults
•ConclusionsAgenda –COVID -19 vaccine effectiveness (VE)
Methods & Context
3
4
Case ControlPerson with acute
respiratory illness
SARS -CoV-2 test
COVID -19
vaccination status
For respiratory viruses, CDC primarily uses case -control studies, including
the test -negative design (TND), to measure vaccine effectiveness (VE)
Effectiveness = 1 – (odds ratio ) x 100% Odds ratio = 𝑂𝑑𝑑𝑠 𝑜𝑓 𝑖𝑚𝑚𝑢𝑛𝑖𝑧𝑎𝑡𝑖𝑜𝑛 𝑐𝑎𝑠𝑒𝑠
𝑂𝑑𝑑𝑠 𝑜𝑓 𝑖𝑚𝑚𝑢𝑛𝑖𝑧𝑎𝑡𝑖𝑜𝑛 𝑐𝑜𝑛𝑡𝑟𝑜𝑙𝑠
VE findings should be interpreted as the
added benefit provided by COVID -19
vaccination in a population with a high
prevalence of vaccine - and infection -induced
immunity.
5VISION Multi -Site Network of Electronic Health Records
>300 emergency departments and urgent cares clinics and >200 hospitals
▪Design: Test-negative design
▪Population: Persons visiting a participating emergency
department or urgent care or hospitalized with COVID -
19-like illness with a SARS -CoV-2 NAAT test result
within 10 days before or 72 hours after encounter
−Cases : CLI with positive NAAT or antigen for SARS -CoV-2
and no positive NAAT for RSV or influenza
−Controls : CLI with negative NAAT for SARS -CoV-2 and no
positive NAAT for influenza (≥18 years) or RSV (≥60 years)
▪Vaccination data: Documented by electronic health records and state and city registries
CLI = COVID -19-like illness; ED/UC = emergency department/urgent care; RSV = respiratory syncytial virus; NAAT = nucleic acid am plification test
CLI is defined based on the presence of specific discharge diagnosis codes. Additional methods available: Link -Gelles, et al. MM WR.
https://www.cdc.gov/mmwr/volumes/74/wr/mm7406a1.htm
6
•Case infants: hospitalized for COVID -19 as the primary reason
for admission and with a positive SARS -CoV-2 NAAT or antigen
test result
•Control infants: hospitalized for COVID -19-like illness and
negative SARS -CoV-2 NAAT result, matched to case infants by
site; hospitalized within 4 weeks of case infant admissionOvercoming COVID -19 Network
•Design: Case -control study to assess
effectiveness of maternal vaccination
against COVID -19-related hospitalizations in
infants <6 months of age
•Population: 26 pediatric hospitals in 20
states
•Data collection: Baseline demographic and
clinical characteristics obtained via chart
abstraction and parent interview
•Vaccination status: Maternal vaccination
status verified using state vaccination
registries, electronic medical records, or
other sources
6
7IVY Network —26 hospitals, 20 U.S. States
•Design : Test-negative, case -control design
•Population : Adults ages ≥18 years hospitalized with COVID -19-
like illness* and SARS -CoV-2 test results within 10 days of
illness onset and 3 days of admission
–Cases: CLI and test positive for SARS -CoV-2 by NAAT or antigen
–Controls : CLI and test negative for SARS -CoV-2, influenza (≥18
years) and RSV (≥60 years) by RT -PCR
•Vaccination data: Electronic medical records, state and city
registries, and plausible self -report
•Specimens: Nasal swabs obtained on all patients for central
RT-PCR testing and whole genome sequencing
*COVID -19-like illness = CLI; CLI is defined as presence of any one of the following: fever, cough, shortness of breath, chest imaging consistent with pneumoni a, or hypoxemia
NAAT = nucleic acid amplification test
8Measuring COVID -19 Vaccine Effectiveness (VE)
Measure Definition* Example
vaccinated
groupExample comparison group
Absolute VE Compares frequency of health outcomes in
vaccinated and unvaccinated people Received original
monovalent doseReceived no COVID -19 vaccines ever
Relative VE Compares frequency of health outcomes in
people who received one type of vaccine to
people who received a different vaccineReceived bivalent
doseEligible for, but did not receive,
bivalent COVID -19 vaccine , but
received original monovalent dose
VE of 2023 -2024
COVID -19 vaccinesCompares people who received 2023 -2024
COVID -19 vaccine to people who did not,
regardless of past COVID -19 vaccinationReceived
2023 -2024 doseEligible for, but did not receive, a
2023 -2024 dose , regardless of past
COVID -19 vaccination history
VE of 2024 -2025
COVID -19 vaccinesCompares people who received 2024 -2025
COVID -19 vaccine to people who did not,
regardless of past COVID -19 vaccinationReceived
2024 -2025 doseEligible for, but did not receive, a
2024 -2025 dose , regardless of past
COVID -19 vaccination history
* Prior SARS -CoV-2 infection is not generally considered, as it is documented inconsistently in medical records.
9COVID -19 Vaccination Coverage Among Children and Adolescents 6 Months -17
Years, by Season and Age Group, National Immunization Survey, 2023 -2025
Weekly estimates of COVID -19 vaccination coverage for vaccination among children through December 31, 2023, were calculated usin g data from the National Immunization Survey –Child COVID Module (NIS –
CCM) . The NIS –CCM was discontinued at the end of 2023 and questions regarding COVID -19 vaccination status and intent were added to t heNational Immunization Survey –Flu (NIS–Flu).
NIS–CCM and NIS –Flu are national random -digit dial cellular telephone surveys of households with children ages 6 months through 17 years; NIS –Flu is conducted during October -June. The respondent to a NIS –
Flu survey is a parent or guardian who said they were knowledgeable about the child's vaccination history. All estimates are based upon parental report of receipt of vaccination and month of that vaccination.
More information : https://www.cdc.gov/covidvaxview/weekly -dashboard/child -coverage -vaccination.html 0%25%50%75%100%
Sep Oct Nov Dec Jan Feb Mar AprCOVID -19 vaccine coverage (%)
Month6 months-4 years, 2023-2024
6 months-4 years, 2024-2025
5-17 years, 2023-2024
5-17 years, 2024-2025
10COVID -19 Vaccination Coverage Among Adults ≥18 Years, 2023 -2024 and
2024 -2025, NIS -ACM
National Immunization Survey -Adult COVID Module: Data from adults age ≥18 years are collected by telephone interview using a random -digit -dialed sample of cell telephone numbers stratified by
state, the District of Columbia, five local jurisdictions (Bexar County TX, Chicago IL, Houston TX, New York City NY, and Phi ladelphia County PA), and Puerto Rico and the U.S. Virgin Islands. Data are
weighted to represent the non -institutionalized U.S. population and mitigate possible bias that can result from an incomplete sa mple frame (exclusion of households with no phone service or only
landline telephones) or non -response. All responses are self -reported. For more information about the survey, see https://www.cd c.gov/nis/about/index.html.0%25%50%75%100%
Sept Week 1
Sept Week 2
Sept Week 3
Sept Week 4
Oct Week 1
Oct Week 2
Oct Week 3
Oct Week 4
Nov Week 1
Nov Week 2
Nov Week 3
Nov Week 4
Dec Week 1
Dec Week 2
Dec Week 3
Dec Week 4
Jan Week 1
Jan Week 2
Jan Week 3
Jan Week 4
Feb Week 1
Feb Week 2
Feb Week 3
Feb Week 4
Mar Week 1
Mar Week 2
Mar Week 3
Mar Week 4
Mar Week 5
Apr Week 1
Apr Week 2
Apr Week 3
Apr Week 4
May Week 1
May Week 2
May Week 3
May Week 4
Jun Week 1
Jun Week 2
Jun Week 3
Jun Week 4
Jun Week 5
Jul Week 1
Jul Week 2
Jul Week 3
July Week 4
Aug Week 1
Aug Week 2
Aug Week 3COVID -19 Vaccination Coverage (%)
Week2023-2024 COVID-19 Vaccination Coverage 2024-2025 COVID-19 Vaccination Coverage
Medicare fee -for-service beneficiaries aged ≥65 years were more likely to receive a
2024 -2025 COVID -19 vaccine dose if they had an underlying medical condition
Fee-for-Service: enrolled in Medicare Parts A/B (and not Part C) for 365 days prior to reporting period. Estimates are based on data released by Medicare claims data through January 2025; data may be incomplete
after December 7, 2024, due to 6 -week reporting lag. Data on uptake by season, race, and ethnicity can be accessed at: https://www.cdc.gov/covidvaxview/weekly -dashboard/adults -65yrs -older -vaccination.html .
Data on uptake by underlying medical condition from internal, unpublished analyses.32%29%
28%
24%
0%25%50%75%100%
08/25/24 -
09/07/2409/08/24 -
09/21/2409/22/24 -
10/05/2410/06/24 -
10/19/2410/20/24 -
11/02/2411/03/24 -
11/16/2411/17/24 -
11/30/2412/01/24 -
12/14/2412/15/24 -
12/28/2412/29/24 -
01/11/2501/12/25 -
01/25/25% with ≥1 2024 -2025 COVID -19 vaccine dose
Two -week periodWeekly cumulative COVID -19 vaccination coverage, by underlying medical condition status,
Medicare fee -for-service beneficiaries aged ≥65 years, August 2024 -January 2025
Any immunocompromising condition
Any underling medical condition
Overall
No underlying medical condition
Estimates of COVID -19 Vaccine
Effectiveness in Children
12
Cumulative rates of COVID -19 hospitalizations for the 2024 –
2025 season are lower compared to 2023 -2024 season.
13020406080100120
Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May JunHospitalizations per 100,000
population
Hospitalization monthCumulative Rates of COVID -19-Associated Hospitalizations among children and adolescents aged ≤17 years,
by Surveillance Season* — COVID -NET, July 2023 –May 2025
≤4 years, 2023 –2024 5–17 years, 2023 –2024
≤4 years, 2024 –2025 5–17 years, 2024 –2025
* Seasons are defined as July through June. The 2024 –2025 season shows data from July 2024 –April 2025 and is ongoing.
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.
14Age group | COVID -19 vaccination statusTotal
encountersSARS -CoV -2-
test -positive, N (%)Median interval since
last dose among
those vaccinated,
days (IQR) Adjusted vaccine effectiveness % (95% CI)
No updated 2023 -2024 COVID -19 vaccine dose*
9 months -4 years 43,246 1,886 (4) 367 (250 to 461) Ref
5-17 years 54,310 2,071 (4) 679 (491 to 810) Ref
≥18 years 279,733 31,167 (11) 756 (61 -189) Ref
2023 -2024 COVID -19 dose received 7 -59 days earlier
9 months -4 years 725 18 (2) 32 (20 to 46) 53 (24 to 70)
5-17 years 951 16 (2) 34 (19 to 47) 64 (41 to 78)
≥18 years 16,082 1,228 (8) 34 (21 -47) 49 (46 to 52)
2023 -2024 COVID -19 dose received 60 -299 days earlier
9 months -4 years 1,345 48 (4) 129 (91 to 178) 23 ( -4 to 43)
5-17 years 2,510 63 (3) 138 (100 to 185) 34 (14 to 49)
≥18 years 49,824 4,701 (9) 149 (100 -211) 12 (8 to 15)VE of 2023 –2024 COVID -19 vaccine doses against emergency
department/urgent care encounters — VISION
September 2023 – August 2024
-20 0 20 40 60 80 100
CDC, unpublished data
* Includes all individuals who did not receive a 2023 -2024 COVID -19 vaccine. For those aged ≥5 years, this includes unvaccinated persons and persons who were vaccinated with ≥1 original
monovalent or bivalent COVID -19 doses. For those aged <5 years, both those in the referent group and those in the vaccinated gro up were required to have completed an initial series. The 2023 -
2024 dose could have been part of the initial series or in addition to the initial series.
Vaccine effectiveness was calculated by comparing the odds of COVID -19 vaccination in case -patients and control -patients using t he equation: (1 – adjusted odds ratio) x 100%. Odds
ratios were estimated by multivariable logistic regression. The odds ratio was adjusted for age, sex, race and ethnicity, cal end ar day, and geographic region.
15Age group | COVID -19 vaccination statusTotal
encountersSARS -CoV -2-
test -positive, N (%)Median interval since
last dose among
those vaccinated,
days (IQR) Adjusted vaccine effectiveness % (95% CI)
No updated 2024 -2025 COVID -19 vaccine dose*
9 months -4 years 31,060 809 (3) 392 (282 -662) Ref
5-17 years 38,870 926 (2) 972 (710 -1,116) Ref
≥18 years 200,933 12,927 (6) 1,068 (742 -1,224) Ref
2024 -2025 COVID -19 dose received 7 -179 days earlier
9 months -4 years 393 2 (1) 64 (30 -98) 79 (17 to 95)
5-17 years 2,208 22 (1) 81 (44 -122) 57 (33 to 72)
≥18 years 40,043 1,694 (4) 89 (50 -129) 34 (30 to 37)VE of 2024 -2025 COVID -19 vaccine doses against emergency
department/urgent care encounters — VISION
September 2024 – May 2025
-20 0 20 40 60 80 100
CDC, unpublished data
* Includes all individuals who did not receive a 2024 -2025 COVID -19 vaccine. For those aged ≥5 years, this includes unvaccinated persons and persons who were vaccinated with ≥1 original
monovalent or bivalent COVID -19 doses. For those aged <5 years, both those in the referent group and those in the vaccinated gro up were required to have completed an initial series. The 2024 -
2025 dose could have been part of the initial series or in addition to the initial series.
Vaccine effectiveness was calculated by comparing the odds of COVID -19 vaccination in case -patients and control -patients using t he equation: (1 – adjusted odds ratio) x 100%. Odds
ratios were estimated by multivariable logistic regression. The odds ratio was adjusted for age, sex, race and ethnicity, cal end ar day, and geographic region.
Overcoming COVID -19: Effectiveness* of maternal vaccination† in
prevention of COVID -19–associated hospitalization among infants§
March 9, 2022 – May 31, 2023
Simeone & Zambrano et al., MMWR, 2023: https://www.cdc.gov/mmwr/volumes/72/wr/mm7239a3.htm .
* VE estimates were based on odds of maternal vaccination during pregnancy in case -patients versus control patients, adjusted fo r U.S. Census Bureau region, admission date (monthly), age (in months),
sex, and race and ethnicity (non -Hispanic Black or African American, non -Hispanic White, non -Hispanic other, Hispanic or Latino of any race, or unknown). Study site was included as a repeated effect.
VE was calculated as (1 – adjusted odds ratio) x 100%.
†Maternal vaccination status was based on the last date of a COVID -19 mRNA vaccine dose: unvaccinated was defined as mothers who had not received any vaccine dose before or during pregnancy,
and vaccinated was defined as mothers who received their last dose of a COVID -19 mRNA vaccine between the first day of pregnancy and 14 days before delivery. Among those vaccinated during
pregnancy, mothers could have received ≥1 dose during pregnancy. Mothers could receive 1 dose of Ad.26.CoV2.S (Janssen [Johns on & Johnson]) vaccine before or during pregnancy and 1 dose of an
mRNA vaccine during pregnancy. Mothers who received only 1 dose of an mRNA vaccine were considered partially vaccinated and w ere excluded from the analysis. Mothers whose last vaccine dose
occurred before pregnancy were excluded from the analysis.
§Infants were excluded from analysis if they were born to mothers who had received their most recent dose before pregnancy, re ceived only 1 dose of an mRNA vaccine, received their most recent
vaccine dose within 14 days of delivery, received only 1 dose of a viral vector vaccine, or whose vaccination status could no t be verified or whose timing of vaccination was unknown.16Age group of infantNo. vaccinated/Total no. (%)
Interval between last vaccine dose and infant
hospitalization, days (IQR)Effectiveness of Maternal Vaccination against Infant Covid -19
Hospitalization % (95% CI) Case -patients Control patients
0-5 months 82/377 (22) 94/339 (28) 236 (185 –300) 35 (15 –51)
0-2 months 43/227 (19) 63/214 (29) 219 (152 –264) 54 (32 –68)
0 20 40 60 80 100
Vaccine Effectiveness (%)
Estimates of COVID -19 Vaccine
Effectiveness in Adults
17
Absolute VE of COVID -19 original monovalent and bivalent doses received prior to or during
pregnancy against COVID -19–associated emergency department/urgent care encounters
among immuno competent pregnant women aged 18 -45 years — VISION
June 2022 – August 2023
Vaccine effectiveness was calculated by comparing the odds of COVID -19 vaccination in case -patients and control -patients using t he equation: (1 – adjusted odds ratio) x 100%. Odds ratios were estimated by
multivariable logistic regression. The odds ratio was adjusted for a ge, ethnicity, race, underlying medical conditions, gestational age at encounter, site, Medicaid status, day of encounter, site facility
urbanicity.
Pregnant women were classified as (1) unvaccinated (no COVID -19 vaccine doses) or (2) vaccinated with the last COVID -19 vaccine dose ≥7 days before the index date (including the original
monovalent and/or bivalent vaccines). The index date was defined as (1) the collection date of a respiratory specimen associa ted with the most recent positive or negative SARS -CoV-2 test result
before the ED/UC encounter or (2) the encounter date, if testing occurred only after the encounter. COVID -19 vaccination dates a nd vaccine types were identified by electronic medical records.
Original monovalent COVID -19 vaccines (11 December 2020 –31 August 2022) include Moderna, Pfizer -BioNTech, and Janssen (Johnson & Johnson), and bivalent COVID -19 vaccines include Moderna
and Pfizer -BioNTech. Bivalent vaccines (1 September 2022 –10 September 2023) contain components from the SARS -CoV-2 ancestral and Omicron BA.4/BA.5 strains.
Ciesla et al., OFID 2024, https://academic.oup.com/ofid/article/11/9/ofae481/7743292 18Vaccine Dosage PatternTotal
testsSARS -CoV-2-
test-positive,
N (%)Median interval
since last dose,
days (IQR)Adjusted VE
(95% CI)
Absolute VE
Unvaccinated (ref) 2991 403 (13) -- Ref
Most recent monovalent or bivalent dose received:
≥6 months before pregnancy 3014 365 (12) 483 (393,579) 6 (-11, 21)
<6 months before pregnancy 1203 143 (12) 267 (204, 325) 28 (11, 42)
During pregnancy 469 35 (7) 91 (45, 158) 52 (29, 67)
-20 020406080100
Vaccine Effectiveness (%)
VISION: VE of 2023 -2024 COVID -19 vaccination against COVID -19–associated
emergency department/urgent care encounters among immuno competent
women aged 18 -45 years, by pregnancy status — VISION
September 2023 – August 2024
VE=vaccine effectiveness; CLI = COVID -19-like illness
Vaccine eff ectiveness was calculated by comparing the odds of COVID -19 vaccination in case -patients and control -patients using the equation : (1 – adjusted odds ratio) x 100%. Odds
ratios were estimated by multivariable logistic regression. The odds ratio was adju sted for: age, ethnicity, race, underlying medical conditions, gestational age at encounter, site,
Medicaid status, day of encounter, site facility urbanicity
CDC unpublished data 19Vaccine Dosage PatternTotal
testsSARS -CoV-2-
test-positive,
N (%)Median interval
since last dose,
days (IQR)Adjusted VE
(95% CI)
Pregnant at CLI encounter
No 2023 -2024 dose (ref) 5058 709 (14) 797 (648, 931) Ref
Most recent 2023 -2024 dose received 7 -179 days 229 13 (6) 77 (44, 120) 58 (24 -77)
Not pregnant at CLI encounter
No 2023 -2024 dose (ref) 76,636 8,052 (11) 794 (641, 931) Ref
Most recent 2023 -2024 dose received 7 -179 days 5,079 313 (6) 83 (45, 126) 37 (29 -44)
-20 020406080100
Vaccine Effectiveness (%)
20Characteristics of emergency department and urgent care encounters and hospitalizations
among adults aged ≥18 years with COVID -19-like illness, by COVID -19 case status and CDC
vaccine effectiveness network — VISION and IVY Networks
September 2024 –May 2025
CharacteristicVaccine effectiveness network and setting, no. (column %)
VISION
ED/UC encounters,
all adults aged ≥18 yearsVISION
hospitalizations,
all adults aged ≥65 yearsIVY
hospitalizations,
all adults aged ≥65 years
TotalCOVID -19
case -
patientsCOVID -19
control -
patients TotalCOVID -19
case -
patientsCOVID -19
control -
patients TotalCOVID -19
case -
patientsCOVID -19
control -
patients
Total 240,976 14,621 226,355 65,751 4,341 61,410 4,392 1,190 3,202
Median age 52 [34, 71] 57 [36, 74] 52 [34, 71] 78 [71, 84] 79 [73, 86] 78 [71, 84] 75 [70, 82] 77 [71, 84] 75 [69, 81]
Age group
18-64 years 158,028 (66) 8,688 (59) 149,340 (66) -- -- -- -- -- --
≥65 years 82,948 (34) 5,933 (41) 77,015 (34) 65,751 (100) 4,341 (100) 61,410 (100) 4,392 (100) 1,190 (100) 3,202 (100)
Immunocompromised* -- -- -- 15,350 (23) 883 (20) 14,467 (24) 1,137 (26) 258 (22) 879 (28)
Updated from Link -Gelles, et al. MMWR: https://www.cdc.gov/mmwr/volumes/74/wr/mm7406a1.htm
ED/UC = emergency department/urgent care; VISION data go through May 2025; IVY data go through April 2025
* Immunocompromised status is not evaluated for ED/UC encounters due to a higher likelihood of incomplete discharge diagnosis codes in this setting.
21Effectiveness of 2024–2025 COVID -19 vaccination against COVID -19–associated emergency
department/urgent care encounters by age group — VISION
September 2024 – May 2025
Updated from: Link -Gelles, et al. MMWR: https://www.cdc.gov/mmwr/volumes/74/wr/mm7406a1.htm . Vaccine effectiveness was calculated by comparing the odds of 2024 –2025 COVID -19 vaccination in case -patients and control -patients using the equation: (1 – adjusted odds
ratio) x 100%. Odds ratios were estimated by multivariable logistic regression. The odds ratio was adjusted for age, sex, rac e and ethnicity, calendar day, and geographic region. The “no 2024 –2025 dose” group included all eligible persons who did not recei ve a 2024 –2025 COVID -19
vaccine dose, regardless of number of previous COVID -19 vaccine doses (if any) received. * Time since vaccination is for most r ecent dose, which could have been an original monovalent, bivalent, 2023 -2024, or 2024 -2025 COVID -19 vaccine.Age group/2024 -2025 COVID -19 vaccination
status/days since doseCOVID -19
case -patients
N (Col %)COVID -19
control -patients
N (Col %)Median interval since
last dose among
vaccinated*, days (IQR) Adjusted vaccine effectiveness % (95% CI)
≥18 years
No 2024 -2025 COVID -19 dose (Ref) 12,927 (88) 188,006 (83) 1,068 (742 -1,224) Ref
Received 2024 -2025 COVID -19 dose 7–179 days earlier 1,694 (12) 38,349 (17) 89 (50 -129) 34 (30 -37)
2024 -2025 COVID -19 dose , 7–59 days earlier 572 (4) 11,763 (5) 34 (21 -47) 36 (30 -42)
2024 -2025 COVID -19 dose , 60–119 days earlier 695 (5) 14,685 (6) 89 (74 -104) 35 (29 -40)
2024 -2025 COVID -19 dose , 120 –179 days earlier 427 (3) 11,901 (5) 147 (133 -162) 28 (20 -35)
18-64 years
No 2024 -2025 COVID -19 dose (Ref) 8,212 (95) 136,067 (91) 1,105 (866 -1,245) Ref
Received 2024 -2025 COVID -19 dose 7–179 days earlier 476 (5) 13,273 (9) 86 (48 -127) 32 (25 -38)
2024 -2025 COVID -19 dose , 7–59 days earlier 156 (2) 4,244 (3) 33 (20 -46) 39 (29 -49)
2024 -2025 COVID -19 dose , 60–119 days earlier 199 (2) 5,155 (3) 89 (74 -104) 32 (21 -41)
2024 -2025 COVID -19 dose , 120 –179 days earlier 121 (1) 3,874 (3) 147 (132 -163) 20 (4 -34)
≥65 years
No 2024 -2025 COVID -19 dose (Ref) 4,715 (79) 51,939 (67) 907 (448 -1,166) Ref
Received 2024 -2025 COVID -19 dose 7–179 days earlier 1,218 (21) 25,076 (33) 91 (51 -131) 35 (30 -39)
2024 -2025 COVID -19 dose , 7–59 days earlier 416 (7) 7,519 (10) 34 (21 -47) 36 (29 -43)
2024 -2025 COVID -19 dose , 60–119 days earlier 496 (8) 9,530 (12) 90 (75 -105) 36 (29 -42)
2024 -2025 COVID -19 dose , 120 –179 days earlier 306 (5) 8,027 (10) 147 (133 -162) 30 (21 -39)
0 20 40 60 80 100
Vaccine effectiveness (%)
22Effectiveness of 2024–2025 COVID -19 vaccination against COVID -19–associated hospitalization
among immunocompetent adults aged ≥65 years — VISION and IVY Networks
September 2024 – May 2025
Network/2024 -2025 COVID -19 vaccination status/days
since doseCOVID -19
case -
patients
N (Col %)COVID -19
control -
patients
N (Col %)Median interval since
last dose among
vaccinated*, days (IQR) Adjusted vaccine effectiveness % (95% CI)
VISION
No 2024 -2025 COVID -19 dose (Ref) 2,943 (85) 34,900 (74) 958 (508 -1,187) Ref
Received 2024 -2025 COVID -19 dose 7–179 days earlier 515 (15) 12,043 (26) 92 (51 -132) 44 (38 -50)
2024 -2025 COVID -19 dose , 7–59 days earlier 155 (4) 3,604 (8) 34 (20 -47) 46 (36 -54)
2024 -2025 COVID -19 dose , 60–119 days earlier 207 (6) 4,509 (10) 90 (75 -104) 50 (42 -57)
2024 -2025 COVID -19 dose , 120 –179 days earlier 153 (4) 3,930 (8) 147 (133 -162) 32 (19 -43)
IVY
No 2024 -2025 COVID -19 dose (Ref) 822 (88) 1,824 (79) Not available Ref
Received 2024 -2025 COVID -19 dose 7–179 days earlier 110 (12) 499 (21) 92 (55 –130) 46 (32 -58)
2024 -2025 COVID -19 dose , 7–59 days earlier 43 (5) 124 (5) 32 (20 –46) 42 (16 -60)
2024 -2025 COVID -19 dose , 60–119 days earlier 37 (4) 205 (9) 89 (73 –103) 53 (32 -68)
2024 -2025 COVID -19 dose , 120 –179 days earlier 30 (3) 170 (7) 146 (130 –161) 40 (9 -62)
0 20 40 60 80 100
Vaccine effectiveness (%)Updated from: Link -Gelles, et al. MMWR: https://www.cdc.gov/mmwr/volumes/74/wr/mm7406a1.htm
Vaccine effectiveness was calculated by comparing the odds of 2024 –2025 COVID -19 vaccination in case -patients and control -patien ts using the equation: (1 – adjusted odds ratio) x 100%. Odds ratios
were estimated by multivariable logistic regression. For VISION, the odds ratio was adjusted for age, sex, race and ethnicity , calendar day, and geographic region. For IVY, the odds ratio was adjusted
for age, sex, race and ethnicity, geographic region (U.S. Department of Health and Human Services Region) and calendar time ( biweekly intervals). The “no 2024 –2025 dose” group included all eligible
persons who did not receive a 2024 –2025 COVID -19 vaccine dose, regardless of number of previous COVID -19 vaccine doses. VISION data go through May 2025; IVY data go through April 2025.
*Time since vaccination is for most recent dose, which could have been an original monovalent, bivalent, 2023 -2024, or 2024 -2025 COVID -19 vaccine.
23Effectiveness of 2024–2025 COVID -19 vaccination against COVID -19–associated critical illness
among immunocompetent adults aged ≥65 years — VISION and IVY Networks
September 2024 – May 2025
2024 -2025 COVID -19 vaccination status/days since
doseCOVID -19
case -
patients
N (Col %)COVID -19
control -
patients
N (Col %)Median interval since
last dose among
vaccinated*, days (IQR) Adjusted vaccine effectiveness % (95% CI)
VISION
No 2024 -2025 COVID -19 dose (Ref) 558 (85) 34,900 (74) 961 (510 -1,189) Ref
Received 2024 -2025 COVID -19 dose 7–179 days earlier 97 (15) 12,043 (26) 92 (51 -132) 45 (31 -56)
2024 -2025 COVID -19 dose , 7–59 days earlier 28 (4) 3,604 (8) 34 (20 -47) 46 (21 -64)
2024 -2025 COVID -19 dose , 60–119 days earlier 44 (7) 4,509 (10) 90 (75 -104) 45 (25 -60)
2024 -2025 COVID -19 dose , 120 –179 days earlier 25 (4) 3,930 (8) 147 (133 -162) 43 (13 -62)
IVY
Acute respiratory failure
No 2024 -2025 COVID -19 dose (Ref) 158 (88) 1,817 (78) Not available Ref
Received 2024 -2025 COVID -19 dose 7–179 days earlier 21 (12) 498 (22) 96 (59 -131) 44 (11 -67)
ICU admission or death
No 2024 -2025 COVID -19 dose (Ref) 141 (91) 1,824 (79) Not available Ref
Received 2024 -2025 COVID -19 dose 7–179 days earlier 14 (9) 499 (21) 96 (60 -133) 56 (23 -76)
Invasive mechanical ventilation or death
No 2024 -2025 COVID -19 dose (Ref) 74 (94) 1,824 (79) Not available Ref
Received 2024 -2025 COVID -19 dose 7–179 days earlier 5 (6) 499 (21) 97 (60 -133) 70 (35 -89)
0 20 40 60 80 100
Vaccine effectiveness (%)
Based on methods in: Link -Gelles, et al. MMWR: https://www.cdc.gov/mmwr/volumes/74/wr/mm7406a1.htm
Vaccine effectiveness was calculated by comparing the odds of 2024 –2025 COVID -19 vaccination in case -patients and control -patien ts using the equation: (1 – adjusted odds ratio) x 100%. Odds ratios were estimated by multivariable logistic regression. For VI SION,
the odds ratio was adjusted for age, sex, race and ethnicity, calendar day, and geographic region. For IVY, the odds ratio wa s adjusted for age, sex, race and ethnicity, geographic region (U.S. Department of Health and Human Services Region) and calenda r time
(biweekly intervals). The “no 2024 –2025 dose” group included all eligible persons who did not receive a 2024 –2025 COVID -19 vacci ne dose, regardless of number of previous COVID -19 vaccine doses. VISION data go through May 2025; IVY data go through April 202 5.
For VISION, critical illness is defined as admission to the intensive care unit or in -hospital death. For IVY, acute respiratory failure was defined as new receipt of high -flow nasal canula, noninvasive ventilation, or invasive mechanical ventilation.
*Time since vaccination is for most recent dose, which could have been an original monovalent, bivalent, 2023 -2024, or 2024 -2025 COVID -19 vaccine.
ICU = intensive care unit
24Effectiveness of 2024–2025 COVID -19 vaccination against COVID -19–associated hospitalization
among immunocompromised adults aged ≥65 years — VISION and IVY Networks
September 2024 – May 2025
Network/2024 -2025 COVID -19 vaccination status/days
since doseCOVID -19
case -
patients
N (Col %)COVID -19
control -
patients
N (Col %)Median interval since
last dose among
vaccinated*, days (IQR) Adjusted vaccine effectiveness % (95% CI)
VISION
No 2024 -2025 COVID -19 dose (Ref) 719 (81) 10,035 (69) 882 (451 -1,166) Ref
Received 2024 -2025 COVID -19 dose 7–179 days earlier 164 (19) 4,432 (31) 93 (53 -133) 38 (25 -48)
2024 -2025 COVID -19 dose , 7–59 days earlier 62 (7) 1,247 (9) 35 (20 -47) 25 (2 -43)
2024 -2025 COVID -19 dose , 60–119 days earlier 61 (7) 1,689 (12) 89 (75 -104) 47 (30 -60)
2024 -2025 COVID -19 dose , 120 –179 days earlier 41 (5) 1,496 (10) 147 (133 -163) 39 (14 -57)
IVY
No 2024 -2025 COVID -19 dose (Ref) 214 (83) 670 (76) Not available Ref
Received 2024 -2025 COVID -19 dose 7–179 days earlier 44 (17) 209 (24) 82 (48 -133) 36 (6 -57)
0 20 40 60 80 100
Vaccine effectiveness (%)
Updated from: Link -Gelles, et al. MMWR: https://www.cdc.gov/mmwr/volumes/74/wr/mm7406a1.htm
Vaccine effectiveness was calculated by comparing the odds of 2024 –2025 COVID -19 vaccination in case -patients and control -patien ts using the equation: (1 – adjusted odds ratio) x 100%. Odds
ratios were estimated by multivariable logistic regression. For VISION, the odds ratio was adjusted for age, sex, race and et hnicity, calendar day, and geographic region. For IVY, the odds ratio was
adjusted for age, sex, race and ethnicity, geographic region (U.S. Department of Health and Human Services Region) and calend ar time (biweekly intervals). The “no 2024 –2025 dose” group included
all eligible persons who did not receive a 2024 –2025 COVID -19 vaccine dose, regardless of number of previous COVID -19 vaccine do ses (if any) received. VISION data go through May 2025; IVY data
go through April 2025.
* Time since vaccination is for most recent dose, which could have been an original monovalent, bivalent, 2023 -2024, or 2024 -2025 COVID -19 vaccine.
25IVY: Effectiveness of 2024–2025 COVID -19 vaccine against hospitalization
among adults aged ≥18 years by SARS -CoV-2 lineage using viral whole -
genome sequencing
•Population
•Cases: COVID -like illness (CLI) and test positive for SARS -CoV-2*;restricted to patients with sequence -
confirmed†KP.3.1.1 lineage (Nextstrain clade 24E) or XEC lineage (Nextstrain clade 24F)
•Controls: CLI and test negative forSARS -CoV-2, influenza viruses, and RSV (≥60 years) byRT-PCR
•Analytic Period: September 1, 2024 –April 27, 2025
•VE§ against hospitalization was calculated separately using case -patients with sequence -confirmed SARS -
CoV-2 KP .3.1.1 and XEC lineage infections
* Case patients who were co -infected with influenza viruses or RSV were excluded.
† Identification of a SARS -CoV-2 lineage through viral whole -genome sequencing was successful for 49% of case -patients during the analysis period.
§ Vaccine effectiveness was calculated by comparing the odds of 2024 –2025 COVID -19 vaccination in case -patients and control -patien ts using the equation: (1 – adjusted odds ratio) x 100%.
Odds ratios were estimated by multivariable logistic regression. The odds ratio was adjusted for age, sex, race and ethnicity, geographic region (U.S. Department of Health and Human Services
Region) and calendar time (biweekly intervals).
Lineage and 2024 -2025 COVID -19
vaccination statusCOVID -19 case -patients COVID -19 control -patients
Vaccine Effectiveness§% (95% CI) N (Col %)Median interval
since last dose
among
vaccinated,
days (IQR) N (Col %)Median interval
since last dose
among
vaccinated,
days (IQR)
KP.3.1.1
No 2024 -2025 COVID -19 dose (Ref) 309 (91) Not available 5,202 (84) Not available Ref
Received 2024 -2025 COVID -19 dose 7–179 days earlier 29 (9) 56 (33 –75) 1,027 (16) 94 (57 –133) 45 (19 –64)
XEC
No 2024 -2025 COVID -19 dose (Ref) 173 (84) Not available 5,202 (84) Not available Ref
Received 2024 -2025 COVID -19 dose 7–179 days earlier 32 (16) 87 (52 –112) 1,027 (16) 94 (57 –133) 34 (2 –57)
* These results include both immunocompetent and immunocompromised persons.
† KP.3.1.1 lineage was defined by Nextstrain clade 24E and XEC lineage was defined by Nextstrain clade 24F.
§ Vaccine effectiveness was calculated by comparing the odds of 2024 –2025 COVID -19 vaccination in case -patients and control -patien ts using the equation: (1 – adjusted odds ratio) x 100%. Odds ratios were
estimated by multivariable logistic regression. The odds ratio was adjusted for age, sex, race and ethnicity, geographic region (U.S. Department of Health and Human Services Re gion) and calendar time
(biweekly intervals).-20 0 20 40 60 80 100
Vaccine Effectiveness (%)IVY: Effectiveness of 2024–2025 COVID -19 vaccine against hospitalization
among adults aged ≥18 years* by SARS -CoV-2 lineage †
September 1, 2024 – April 27, 2025
27•For the respective year, compared to no in -season dose, COVID -19 vaccination provided additional protection
against:
-COVID -19-associated emergency department and urgent care* visits among children ; protection was generally similar across age
groups.
-COVID -19-associated emergency department and urgent care visits among adults .
-COVID -19-associated hospitalizations among adults aged ≥65 years with and without immunocompromising conditions .
-COVID -19-associated critical illness among adults aged ≥65 years ; protection appeared to be higher and more durable against critical
illness compared to less severe outcomes.
•VE should be interpreted as the added benefit of 2023 –2024 or 2024 –2025 COVID -19 vaccination in a population
with high levels of infection -induced immunity, vaccine -induced immunity, or both.
-Prior SARS -CoV-2 infection contributes protection against future disease, though protection wanes over time.
-An increase in SARS -CoV-2 circulation in the United States during late summer 2024, just before the 2024 –2025 COVID -19 vaccines
were approved and authorized, may have resulted in higher population -level immunity against JN.1 -lineage strains, which could ha ve
resulted in lower measured VE than in a population with less recent infection.Conclusions: effectiveness of COVID -19 vaccines
* Due to lower baseline rates of severe disease and lower COVID -19 vaccine coverage, VE against hospitalization and critical ill ness in children could not be estimated.
28Data and analysis were provided by CDC and the
following CDC -funded network partners:
VISION Collaborators
IVY Collaborators
Overcoming Collaborators
Back -up
30Context for interpreting COVID -19 VE across age groups: high infection -
induced seroprevalence in children and adults
* Data on persons aged 0 -17 years from nationwide commercial laboratory testing of residual serum specimens from ~27,000 childre n and adolescents originally submitted for routine screening or clinical management,
https://covid.cdc.gov/covid -data -tracker/#pediatric -seroprevalence
** Data on persons aged ≥16 years from a longitudinal, national cohort of ~35,000 blood donors, https://covid.cdc.gov/covid -data -tracker/#nationwide -blood -donor -seroprevalence -2022 89%
92%
87%
76%16-29 years
30-49 years
50-64 years
≥65 years
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Percent with infection -induced immunityPercent of persons with infection -induced immunity, based on anti -nucleocapsid results from blood donors,
adolescents and adults , October – December 2023**
VE findings should be interpreted as the added benefit provided by COVID -19 vaccination in a
population with a high prevalence infection -induced immunity.91%
93%0-11 years
12-17 yearsPercent of persons with infection -induced immunity, based on anti -nucleocapsid results from residual specimens from commercial l aboratories,
children and adolescents , November – December 2022*Age at blood draw
31Age group/2023 -2024 COVID -19 vaccination
status/days since doseTotal
encountersSARS -CoV -2-
test -positive,
N (%)Median interval since
last dose among
vaccinated, days (IQR) Adjusted VE (95% CI)
≥18 years
No 2023 -2024 COVID -19 dose (ref) 279,733 31,167 (11) 756 (543 -920) ref
2023 -2024 COVID -19 dose , 7-299 days earlier 65,906 5,929 (9) 117 (61 -189) 24 (21 to 26)
2023 -2024 COVID -19 dose , 7-59 days earlier 16,082 1,228 (8) 34 (21 -47) 49 (45 to 52)
2023 -2024 COVID -19 dose , 60-119 days earlier 17,653 1,521 (9) 88 (73 -103) 26 (22 to 30)
2023 -2024 COVID -19 dose , 120 -179 days earlier 13,815 875 (6) 147 (133 -163) 18 (12 to 24)
2023 -2024 COVID -19 dose , 180-299 days earlier 18,356 2,305 (13) 231 (204 -261) -7 (-13 to -2)
18-64 years
No 2023 -2024 COVID -19 dose (ref) 200,443 21,053 (10) 789 (624 -934) ref
2023 -2024 COVID -19 dose , 7-299 days earlier 23,655 1,893 (8) 116 (59 -187) 22 (18 to 26)
2023 -2024 COVID -19 dose , 7-59 days earlier 5,952 360 (6) 34 (20 -47) 55 (49 to 59)
2023 -2024 COVID -19 dose , 60-119 days earlier 6,285 436 (7) 88 (74 -104) 29 (22 to 36)
2023 -2024 COVID -19 dose , 120 -179 days earlier 4,971 256 (5) 147 (133 -163) 22 (11 to 31)
2023 -2024 COVID -19 dose , 180-299 days earlier 6,447 841 (13) 230 (203 -260) -24 ( -34 to -14)
≥65 years
No 2023 -2024 COVID -19 dose (ref) 79,290 10,114 (13) 669 (436 -868) ref
2023 -2024 COVID -19 dose , 7-299 days earlier 42,251 4,036 (10) 117 (62 -190) 25 (22 to 28)
2023 -2024 COVID -19 dose , 7-59 days earlier 10,130 868 (9) 34 (21 -47) 46 (41 to 50)
2023 -2024 COVID -19 dose , 60-119 days earlier 11,368 1,085 (10) 88 (73 -103) 25 (20 to 30)
2023 -2024 COVID -19 dose , 120 -179 days earlier 8,844 619 (7) 148 (133 -163) 19 (11 to 26)
2023 -2024 COVID -19 dose , 180-299 days earlier 11,909 1,464 (12) 232 (204 -262) 2 (-5 to 8)VISION: VE of 2023 -2024 COVID -19 vaccine against COVID -19-associated emergency
department/urgent care encounters among immunocompetent adults aged ≥18 years, by age group
September 2023 – August 2024
Link-Gelles et al. in press, JAMA Network Open. VE was calculated as (1 − odds ratio) x 100%, estimated using a test -negative case -control design, with the odds ratio adjusted for age, sex, race and ethnicity,
geographic region, and calendar time. A VE estimate less than zero is possible due to the waning protection from COVID -19 vaccin es coupled with the existing infection -induced immunity in unvaccinated
participants. As protection from vaccination wanes, and unvaccinated people accumulate protection from repeated infections, t his may yield negative VE. -40 -20 0 20 40 60 80 100
32VISION: VE of 2023 -2024 COVID -19 vaccine against COVID -19-associated
hospitalization among immunocompetent adults aged ≥18 years, by age group
September 2023 – August 2024
Age group/2023 -2024 COVID -19 vaccination
status/days since doseTotal
encountersSARS -CoV -2-
test -positive,
N (%)Median interval since
last dose among
vaccinated, days (IQR) Adjusted VE (95% CI)
≥18 years
No 2023 -2024 COVID -19 dose (ref) 87,718 8,480 (10) 733 (507 -918) ref
2023 -2024 COVID -19 dose , 7-299 days earlier 24,213 1,900 (8) 123 (63 -193) 29 (25 to 33)
2023 -2024 COVID -19 dose , 7-59 days earlier 5,618 417 (7) 34 (21 -47) 51 (46 to 56)
2023 -2024 COVID -19 dose , 60-119 days earlier 6,231 486 (8) 88 (74 -104) 36 (30 to 42)
2023 -2024 COVID -19 dose , 120 -179 days earlier 5,275 306 (6) 149 (134 -164) 22 (12 to 31)
2023 -2024 COVID -19 dose , 180-299 days earlier 7,089 691 (10) 230 (203 -260) -4 (-14 to 5)
18-64 years
No 2023 -2024 COVID -19 dose (ref) 35,303 2,229 (6) 788 (606 -940) ref
2023 -2024 COVID -19 dose , 7-299 days earlier 4,249 234 (6) 120 (62 -188) 15 (2 to 27)
2023 -2024 COVID -19 dose , 7-59 days earlier 1,005 60 (6) 33 (21 -46) 31 (10 to 47)
2023 -2024 COVID -19 dose , 60-119 days earlier 1,113 52 (5) 89 (75 -104) 33 (11 to 50)
2023 -2024 COVID -19 dose , 120 -179 days earlier 936 33 (4) 148 (135 -164) 21 ( -12 to 45)
2023 -2024 COVID -19 dose , 180-299 days earlier 1,195 89 (7) 229 (201 -259) -31 ( -66 to -4)
≥65 years
No 2023 -2024 COVID -19 dose (ref) 52,415 6,251 (12) 698 (467 -899) ref
2023 -2024 COVID -19 dose , 7-299 days earlier 19,964 1,666 (8) 123 (63 -194) 31 (27 to 35)
2023 -2024 COVID -19 dose , 7-59 days earlier 4,613 357 (8) 34 (21 -47) 54 (49 to 59)
2023 -2024 COVID -19 dose , 60-119 days earlier 5,118 434 (8) 88 (73 -104) 36 (29 to 42)
2023 -2024 COVID -19 dose , 120 -179 days earlier 4,339 273 (6) 149 (134 -164) 21 (10 to 31)
2023 -2024 COVID -19 dose , 180-299 days earlier 5,894 602 (10) 230 (204 -261) 0 (-10 to 10)
-80 -60 -40 -20 020 40 60 80 100Link-Gelles et al. in press, JAMA Network Open. VE was calculated as (1 − odds ratio) x 100%, estimated using a test -negative case -control design, with the odds ratio adjusted for age, sex, race and ethnicity,
geographic region, and calendar time. A VE estimate less than zero is possible due to the waning protection from COVID -19 vaccin es coupled with the existing infection -induced immunity in unvaccinated
participants. As protection from vaccination wanes, and unvaccinated people accumulate protection from repeated infections, t his may yield negative VE.
IVY: Number of COVID -19 case -patients by hospital admission week and SARS -
CoV-2 lineage
September 1, 2024 –April 27, 2025
Dates are for the start of the admission week.
34*Data sources included Medicare Enrollment Database (EDB) and Common Medicare Environment (CME), Common Working File (CWF) an d Shared System Data (SSD) Medicare Parts A/B claims data, Minimum Data Set (MDS), and CDC/ATSDR
Social Vulnerability Index (SVI)
**Hazard ratios adjusted for age group, sex, race, long/short nursing home stay status, social vulnerability index, state, ru ral/urban classification, number of underlying medical conditions, 2022 -2023 influenza vaccination status, and bivalent
COVID -19 vaccination status.Medicare data
• Design: Retrospective cohort
• Data source: Medicare fee -for-service claims data*
• Population: Persons aged ≥65, recent nursing home
stay
• Censoring events:
– COVID -19-associated thromboembolic event (TE)
– Death
– Disenrollment in Medicare Parts A/B
– Enrollment in Medicare Part C
– Admission to hospice facility
– Dialysis encounter
– Receipt of a 2023 -2024 COVID -19 vaccine dose <60 days from
bivalent COVID -19 vaccine dose
– Receipt of a second 2023 -2024 COVID -19 vaccine dose <120 days
from first 2023 -2024 COVID -19 vaccine dose
– Receipt of a third 2023 -2024 COVID -19 vaccine dose
– End of study period
• VE = (1 - adjusted hazard ratio**) x 100%
where adjusted hazard ratio = 𝑟𝑎𝑡𝑒 𝑜𝑓 𝐶𝑂𝑉𝐼𝐷 −19−𝑎𝑠𝑠𝑜𝑐𝑖𝑎𝑡𝑒𝑑 𝑇𝐸𝑣𝑎𝑐𝑐𝑖𝑛𝑎𝑡𝑒𝑑
𝑟𝑎𝑡𝑒 𝑜𝑓 𝐶𝑂𝑉𝐼𝐷 −19−𝑎𝑠𝑠𝑜𝑐𝑖𝑎𝑡𝑒𝑑 𝑇𝐸𝑢𝑛𝑣𝑎𝑐𝑐𝑖𝑛𝑎𝑡𝑒𝑑
COVID -19 TEOther Censoring Event
Unvaccinated person -time
Vaccinated person -time
Start Follow -up End Study Period
35Age group/2023 -2024 COVID -19 vaccination
status/days since doseNumber of
BeneficiariesNumber of
OutcomesMedian Follow -up Time
Contributed to Category
(Days) Adjusted VE (95% CI)
≥65+ years
No 2023 -2024 COVID -19 dose (ref) 516,176 4,335 142 Ref
2023 -2024 COVID -19 dose , ≥ 7 days earlier 209,228 726 161 31% (25%, 36%)
2023 -2024 COVID -19 dose , 7-59 days earlier 26,646 198 53 50% (42%, 56%)
2023 -2024 COVID -19 dose , 60-119 days earlier 37,426 238 60 29% (20%, 38%)
2023 -2024 COVID -19 dose , 120 -179 days earlier 23,558 138 60 15% (0%, 28%)
2023 -2024 COVID -19 dose , ≥ 180 days earlier 121,598 152 65 0% ( -17%, 14%)
65-74 years
No 2023 -2024 COVID -19 dose (ref) 116,278 1,025 176 Ref
2023 -2024 COVID -19 dose , ≥ 7 days earlier 40,719 132 178 29% (16%, 39%)
2023 -2024 COVID -19 dose , 7-59 days earlier 5,029 34 53 47% (36%, 57%)
2023 -2024 COVID -19 dose , 60-119 days earlier 6,646 55 60 26% (11%, 39%)
2023 -2024 COVID -19 dose , 120 -179 days earlier 4,984 22 60 12% ( -9%, 29%)
2023 -2024 COVID -19 dose , ≥ 180 days earlier 24,060 21 64 -5% ( -29%, 15%)
≥75+ years
No 2023 -2024 COVID -19 dose (ref) 399,898 3,310 135 Ref
2023 -2024 COVID -19 dose , ≥ 7 days earlier 168,509 594 157 31% (25%, 37%)
2023 -2024 COVID -19 dose , 7-59 days earlier 21,617 164 53 50% (42%, 57%)
2023 -2024 COVID -19 dose , 60-119 days earlier 30,780 183 60 30% (20%, 39%)
2023 -2024 COVID -19 dose , 120 -179 days earlier 18,574 116 60 16% (1%, 29%)
2023 -2024 COVID -19 dose , ≥ 180 days earlier 97,538 131 65 1% ( -17%, 16%)VE of 2023 -2024 COVID -19 vaccine against COVID -19 related thromboembolic events among immunocompetent
Medicare fee -for-service beneficiaries residing in a nursing home, by age group and time since vaccination
September 2023 – July 2024
-40 -20 0 20 40 60 80 100
CDC, unpublished data
Models are adjusted for age group, sex, race, long/short NH stay status, social vulnerability index (SVI), state, rural/urban classification, number of UMC categories, 2022 -2023 influenza vaccination status, and bivalent COVID -19 vaccination
status.
Infection -induced SARS -CoV-2 seroprevalence among U.S.
children — September 2021 – December 2022
36
Infection -induced (nucleocapsid
antibody) seroprevalence
Month and Year
Shaded ranges depict 95% confidence intervals for the estimated seroprevalence shown by the dark line in the corresponding co lor.
Source: https://covid.cdc.gov/covid -data -tracker/#pediatric -seroprevalence
Accessed: March 20, 20256-11 months
Population SARS -CoV -2 spike antibody over time by the cumulative
number of combined infections and vaccinations - U.S. blood donors ages
≥16 years, September 2021 -December 2023
Solid lines represent mean anti -spike IgG levels; dotted lines represent model based 25th-75th% percentiles
Higher number of cumulative SARS -CoV-2 infections and COVID -19 vaccinations leads to higher antibody
levels, but with smaller incremental increases in antibodies with each exposure
Spike IgG BAU/mL
Source: https://covid.cdc.gov/covid -data -tracker/#nationwide -blood -donor -seroprevalence -2022 , CDC unpublished data 9
381. Yousaf AR, Mak J, Gwynn L, et al. COVID -19 Vaccination and Odds of Post –COVID -19 Condition Symptoms in Children Aged 5 to 17 Years. JAMA Netw Open. 2025;8(2):e2459672.
2. Mak J, Khan S, Britton A et al. Association of Messenger RNA Coronavirus Disease 2019 (COVID -19) Vaccination and Reductions i n Post COVID Conditions Following Severe Acute Respiratory Syndrome
Coronavirus 2 Infection in a US Prospective Cohort of Essential Workers, The Journal of Infectious Diseases, Volume 231, Issu e 3, 15 March 2025, Pages 665 –676COVID -19 mRNA vaccination associated with reduced occurrence
of Long COVID following COVID -19: June 2021 -September 2022
Among children aged 5 – 17 years:
Completion of the primary vaccine
series prior to infection associated
with reduced likelihood of Long
COVID symptoms1
•57% for 1 or more symptoms
•73% for 2 or more symptoms
•72% for respiratory symptomsAmong adults:
3 doses of original monovalent vaccine
prior to infection associated with
reduced likelihood of Long COVID
symptoms2
•63% for gastrointestinal symptoms
•44% for neurological symptoms
•52% for other non -specific
symptoms
•Data that explicitly quantifies vaccine effectiveness against transmission is ideal,
but it is often not feasible.
•Other data can help us understand the impact of COVID -19 vaccination on
transmission, vaccine effectiveness against infection and infectiousness
-COVID -19 vaccines provide moderate protection against infection in older children and adults.1,2,3
-COVID -19 vaccines may provide less protection against infection in young, infection -naïve
children.4
-COVID -19 vaccines moderately reduce infectiousness in individuals after they are infected with
SARS -CoV-2 (see next slides).5
•Preventing infections further reduces transmission by stopping future transmission
chains. COVID -19 vaccine impact on transmission
1 Feldstein L, et al. Effectiveness of mRNA COVID -19 Vaccines and Hybrid Immunity in Preventing SARS -CoV-2 Infection and Symptomatic COVID -19 Among Ad ults in the United States.
https://academic.oup.com/jid/article/231/4/e743/7945315
2 Feldstein L , et al. Effectiveness of Bivalent mRNA COVID -19 Vaccines in Preventing SARS -CoV-2 Infection in Children and Adolescents Aged 5 to 17 Yea rs. https://jamanetwork.com/journals/jama/fullarticle/2814536
3 Kirwan PD, et al. Protection of vaccine boosters and prior infection against mild/asymptomatic and moderate COVID -19 infection in the UK SIREN hea lthcare worker cohort: October 2023 to March 2024.
https://www.sciencedirect.com/science/article/pii/S0163445324002275?via%3Dihub
4 Feldstein L , et al. Protection From COVID -19 Vaccination and Prior SARS -CoV-2 Infection Among Children Aged 6 Months –4 Years, United States, Septemb er 2022 –April 2023
https://academic.oup.com/jpids/article/14/1/piae121/7917119
5 CDC. Respiratory Illness: Gauge of Household Transmission (RIGHT) Study, unpublished with manuscript in progress.
40COVID -19 Vaccine Effectiveness against SARS -CoV-2 (SCV2) Infectiousness
Respiratory Illness: Gauge of Household Transmission (RIGHT) Study
Prospective household transmission study of SARS -CoV-2, January 2024 –January 2025
Preliminary analysis (unpublished, manuscript in progress) from RIGHT Study shared by research teams at CDC, Vanderbilt Unive rsity Medical Center, University of Washington, and Columbia
University Irvin Medical Center.
Individuals with SARS -CoV-2 infection who had received a COVID -19
vaccination within prior 6 months had lower risk of transmitting to other
household contacts. Vaccine effectiveness at reducing transmission to
others was 45%.
Preliminary analysis (unpublished, manuscript is progress) from RIGHT Study Jan 2024 -Jan 2025 shared by research teams at CDC, V anderbilt University Medical Center, University of Washington, and
Columbia University Irvin Medical Center. *Adjusted for age of contact, COVID -19 vaccination status of contact, age of primary case, enrollment state, number of people in the
home, enrollment timing, and clustering by household
† Vaccine effectiveness against infectionAdjusted* Risk of SARS -CoV-2 Infection in Household Contact by Primary Case Vaccination Status
†