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COVID-19 / SPECIALTY RESEARCH

Public HealthIn perspective.

The key COVID-19 findings in public health, distilled into a clear, readable brief. The evidence is here whenever you want to go deeper.

INSIDE THIS MONITOR
29cited sources
18available findings

Study findings updated

AI-assisted evidence summary. For general information. These findings are not individual medical advice or a clinician endorsement.

THE SHORT VERSION

What’s worth knowing.

The key findings, what they mean, and the context that matters.

THE HEADLINE TAKEAWAY

Estimates for 2025-2026 COVID-19 Vaccines indicated hospitalization protection

An interim test-negative study in adults reported effectiveness of 2025-2026 COVID-19 Vaccines against COVID-19-associated hospitalization, including among adults aged 65+.

Neither the comparator for recipients of 2025-2026 COVID-19 Vaccines nor the follow-up period is available in this summary, so the effectiveness percentages are not featured.

See the evidence

Vaccine effectiveness against COVID-19-associated hospitalization

55%
95% CI: 41%-66%

Wiegand, Ryan E et al.. Interim Estimated Effectiveness of 2025-2026 COVID-19 Vaccines in Adults Using a Test-Negative Design.. JAMA network open. 2026.

Vaccine effectiveness against hospitalization in adults aged 65+

53%
95% CI: 37%-65%

Wiegand, Ryan E et al.. Interim Estimated Effectiveness of 2025-2026 COVID-19 Vaccines in Adults Using a Test-Negative Design.. JAMA network open. 2026.

02

Hispanic mortality exceeded White mortality in U.S. data

2.3x

Age-adjusted COVID-19 mortality among Hispanic people was 2.3x that among White people in the U.S.

This was a U.S. race and ethnicity mortality report; its study design and the period covered are not available in this summary.

See the evidence

Health Disparity

2.3x
Hispanic vs White mortality ratio (age-adjusted)

APM Research Lab. The color of coronavirus: COVID-19 deaths by race and ethnicity in the U.S. Updated 2021.

03

No clear mortality difference after inter-hospital ICU transfer

No clear difference

Exploratory meta-analyses did not establish a mortality difference between transferred and non-transferred adult COVID-19 ICU patients.

One exploratory analysis pooled 2 studies and another pooled 3; neither adjusted estimate established a difference, and this does not prove equivalence.

See the evidence

The reported result does not establish a difference; it does not prove equivalence.

Adjusted mortality among transferred versus non-transferred adult COVID-19 ICU patients in an exploratory meta-analysis (k=3); the difference was not statistically significant.

OR 1.29
95% CI: 0.84-1.98

Brock, Jonas et al.. Inter-hospital ICU-to-ICU transfer of critically ill COVID-19 patients is not associated with increased mortality: a systematic review with exploratory meta-analysis.. Scientific reports. 2026.

Added

Adjusted mortality among transferred versus non-transferred adult COVID-19 ICU patients in an exploratory meta-analysis (k=2); the difference was not statistically significant.

HR 0.71
95% CI: 0.34-1.46

Brock, Jonas et al.. Inter-hospital ICU-to-ICU transfer of critically ill COVID-19 patients is not associated with increased mortality: a systematic review with exploratory meta-analysis.. Scientific reports. 2026.

Added

04

Sex/gender differences in mental-health changes were unclear

No clear difference

Pre-pandemic-to-pandemic changes in depression, anxiety and stress did not clearly differ between women or females and men or males.

The cohort meta-analyses retained high risk of bias or other methodological limitations; depression and anxiety analyses also had substantial heterogeneity. No clear difference does not mean equal change.

See the evidence

The reported result does not establish a difference; it does not prove equivalence.

Difference between women or females and men or males in prepandemic-to-pandemic change in continuous depression symptoms; minimal and not statistically significant (12 cohorts; 9,750 participants; I2 = 65.4%). Substantial heterogeneity, high risk of bias, or both were present across analyses.

SMD difference 0.10
95% CI: -0.00 to 0.20; 95% PI: -0.23 to 0.43

Sung, Gabriel Chun Yin et al.. Mental Health Symptom Changes by Sex or Gender Before and During the COVID-19 Pandemic: A Systematic Review and Meta-Analysis.. JAMA network open. 2026.

Added

Difference between women or females and men or males in prepandemic-to-pandemic change in continuous anxiety symptoms; minimal and not statistically significant (7 cohorts; 6,039 participants; I2 = 68.7%). Substantial heterogeneity, high risk of bias, or both were present across analyses.

SMD difference 0.09
95% CI: -0.04 to 0.22; 95% PI: -0.27 to 0.45

Sung, Gabriel Chun Yin et al.. Mental Health Symptom Changes by Sex or Gender Before and During the COVID-19 Pandemic: A Systematic Review and Meta-Analysis.. JAMA network open. 2026.

Added

Difference between women or females and men or males in prepandemic-to-pandemic change in continuous stress symptoms; minimal and not statistically significant (8 cohorts; 2,994 participants; I2 = 0%). High risk of bias or other methodological limitations remained present across the analyses.

SMD difference -0.08
95% CI: -0.16 to 0.01; 95% PI: -0.18 to 0.02

Sung, Gabriel Chun Yin et al.. Mental Health Symptom Changes by Sex or Gender Before and During the COVID-19 Pandemic: A Systematic Review and Meta-Analysis.. JAMA network open. 2026.

Added

Study-specific findings. Different populations, treatments and follow-up periods can produce different results.

THE RESEARCH, AS IT ARRIVES

Latest studies.

The newest findings added to this collection.
The learning from each, already distilled.

  1. STUDY 01Findings added
    TL;DR

    Wellbeing was associated with Long COVID and vaccination

    The highest versus lowest CASP-12 psychological wellbeing group had lower odds of long COVID and higher odds of COVID-19 vaccination.

    This association was reported in Europeans aged at least 50 years; it does not establish that wellbeing caused either outcome.

    Study details & original results

    Gao, Yumeng et al.. Association between psychological wellbeing and the COVID-19-related outcomes in Europeans aged ≥ 50 years old: The SHARE study.. Human vaccines & immunotherapeutics. 2026.

    Odds of long COVID among participants in the highest versus lowest CASP-12 psychological wellbeing group, corresponding to 23% lower odds

    OR 0.77
    95% CI: 0.64-0.93

    Odds of COVID-19 vaccination among participants in the highest versus lowest CASP-12 psychological wellbeing group

    OR 2.68
    95% CI: 2.44-2.96

    Citation in Public Health
  2. STUDY 02Findings added
    TL;DR

    No clear mortality difference after inter-hospital ICU transfer

    No clear difference

    Exploratory meta-analyses did not establish a mortality difference between transferred and non-transferred adult COVID-19 ICU patients.

    One exploratory analysis pooled 2 studies and another pooled 3; neither adjusted estimate established a difference, and this does not prove equivalence.

    Study details & original results

    Brock, Jonas et al.. Inter-hospital ICU-to-ICU transfer of critically ill COVID-19 patients is not associated with increased mortality: a systematic review with exploratory meta-analysis.. Scientific reports. 2026.

    Adjusted mortality among transferred versus non-transferred adult COVID-19 ICU patients in an exploratory meta-analysis (k=3); the difference was not statistically significant.

    OR 1.29
    95% CI: 0.84-1.98

    Adjusted mortality among transferred versus non-transferred adult COVID-19 ICU patients in an exploratory meta-analysis (k=2); the difference was not statistically significant.

    HR 0.71
    95% CI: 0.34-1.46

    The reported result does not establish a difference; it does not prove equivalence.

    Citation in Public Health
  3. STUDY 03Findings added
    TL;DR

    Sex/gender differences in symptom changes were unclear

    No clear difference

    Pre-pandemic-to-pandemic changes in depression, anxiety and stress did not clearly differ between women or females and men or males.

    High risk of bias or other methodological limitations remained; depression and anxiety analyses also had substantial heterogeneity. These null results do not prove equal changes.

    Study details & original results

    Sung, Gabriel Chun Yin et al.. Mental Health Symptom Changes by Sex or Gender Before and During the COVID-19 Pandemic: A Systematic Review and Meta-Analysis.. JAMA network open. 2026.

    Difference between women or females and men or males in prepandemic-to-pandemic change in continuous depression symptoms; minimal and not statistically significant (12 cohorts; 9,750 participants; I2 = 65.4%). Substantial heterogeneity, high risk of bias, or both were present across analyses.

    SMD difference 0.10
    95% CI: -0.00 to 0.20; 95% PI: -0.23 to 0.43

    Difference between women or females and men or males in prepandemic-to-pandemic change in continuous anxiety symptoms; minimal and not statistically significant (7 cohorts; 6,039 participants; I2 = 68.7%). Substantial heterogeneity, high risk of bias, or both were present across analyses.

    SMD difference 0.09
    95% CI: -0.04 to 0.22; 95% PI: -0.27 to 0.45

    Difference between women or females and men or males in prepandemic-to-pandemic change in continuous stress symptoms; minimal and not statistically significant (8 cohorts; 2,994 participants; I2 = 0%). High risk of bias or other methodological limitations remained present across the analyses.

    SMD difference -0.08
    95% CI: -0.16 to 0.01; 95% PI: -0.18 to 0.02

    The reported result does not establish a difference; it does not prove equivalence.

    Citation in Public Health
3 of 3 study updates

Dates show when findings were added here, not when papers were published. Study populations and comparisons differ.

WHEN YOU WANT TO GO DEEPER
See all 18 findingsOriginal results, comparisons and study details.
9 of 9 source groupsFindings stay together with their study.
SOURCE 292 findings

Gao, Yumeng et al.. Association between psychological wellbeing and the COVID-19-related outcomes in Europeans aged ≥ 50 years old: The SHARE study.. Human vaccines & immunotherapeutics. 2026.

Odds of COVID-19 vaccination among participants in the highest versus lowest CASP-12 psychological wellbeing group

Added
OR 2.6895% CI: 2.44-2.96Source [29]

Odds of long COVID among participants in the highest versus lowest CASP-12 psychological wellbeing group, corresponding to 23% lower odds

Added
OR 0.7795% CI: 0.64-0.93Source [29]
SOURCE 282 findings

Brock, Jonas et al.. Inter-hospital ICU-to-ICU transfer of critically ill COVID-19 patients is not associated with increased mortality: a systematic review with exploratory meta-analysis.. Scientific reports. 2026.

Adjusted mortality among transferred versus non-transferred adult COVID-19 ICU patients in an exploratory meta-analysis (k=3); the difference was not statistically significant.

Added
OR 1.2995% CI: 0.84-1.98Source [28]

Adjusted mortality among transferred versus non-transferred adult COVID-19 ICU patients in an exploratory meta-analysis (k=2); the difference was not statistically significant.

Added
HR 0.7195% CI: 0.34-1.46Source [28]
SOURCE 273 findings

Sung, Gabriel Chun Yin et al.. Mental Health Symptom Changes by Sex or Gender Before and During the COVID-19 Pandemic: A Systematic Review and Meta-Analysis.. JAMA network open. 2026.

Difference between women or females and men or males in prepandemic-to-pandemic change in continuous anxiety symptoms; minimal and not statistically significant (7 cohorts; 6,039 participants; I2 = 68.7%). Substantial heterogeneity, high risk of bias, or both were present across analyses.

Added
SMD difference 0.0995% CI: -0.04 to 0.22; 95% PI: -0.27 to 0.45Source [27]

Difference between women or females and men or males in prepandemic-to-pandemic change in continuous depression symptoms; minimal and not statistically significant (12 cohorts; 9,750 participants; I2 = 65.4%). Substantial heterogeneity, high risk of bias, or both were present across analyses.

Added
SMD difference 0.1095% CI: -0.00 to 0.20; 95% PI: -0.23 to 0.43Source [27]
All 3 findings from this source

Difference between women or females and men or males in prepandemic-to-pandemic change in continuous stress symptoms; minimal and not statistically significant (8 cohorts; 2,994 participants; I2 = 0%). High risk of bias or other methodological limitations remained present across the analyses.

Added
SMD difference -0.0895% CI: -0.16 to 0.01; 95% PI: -0.18 to 0.02Source [27]
SOURCE 011 finding

Wang H, Paulson KR, Pease SA, et al. Estimating excess mortality due to the COVID-19 pandemic: a systematic analysis of COVID-19-related mortality, 2020-21. Lancet. 2022;399(10334):1513-1536.

Excess Mortality

14.9-28.1MGlobal excess deaths 2020-2023 (95% CI)Source [1]
SOURCE 021 finding

APM Research Lab. The color of coronavirus: COVID-19 deaths by race and ethnicity in the U.S. Updated 2021.

Original source link unavailableView citation [2]

Health Disparity

2.3xHispanic vs White mortality ratio (age-adjusted)Source [2]
SOURCE 031 finding

Davis HE, McCorkell L, Vogel JM, Topol EJ. Long COVID: major findings, mechanisms and recommendations. Nature Reviews Microbiology. 2023;21(3):133-146.

Long COVID Prevalence

6-12%Post-infection persistent symptoms (varies by definition)Source [3]
SOURCE 041 finding

Polack FP, Thomas SJ, Kitchin N, et al. Safety and efficacy of the BNT162b2 mRNA Covid-19 vaccine. N Engl J Med. 2020;383(27):2603-2615.

Vaccine Effectiveness

90-95%mRNA VE against symptomatic infection (95% CI: 88-97%)Source [4]
SOURCE 253 findings

Li, Shen et al.. Global prevalence of prolonged grief disorder during the COVID-19 pandemic under standardized diagnostic frameworks: A systematic review and meta-analysis.. Psychological medicine. 2026.

Pooled prevalence of prolonged grief disorder during COVID-19 pandemic

24%95% CI: 13%-36%Source [25]

PGD prevalence in China, highest among studied regions

43%95% CI: 33%-54%Source [25]
All 3 findings from this source

PGD prevalence by diagnostic criteria: DSM-5-TR vs ICD-11

18% vs. 26%Source [25]
SOURCE 264 findings

Wiegand, Ryan E et al.. Interim Estimated Effectiveness of 2025-2026 COVID-19 Vaccines in Adults Using a Test-Negative Design.. JAMA network open. 2026.

Vaccine effectiveness against COVID-19-associated ED/UC encounters

50%95% CI: 42%-57%Source [26]

Vaccine effectiveness against COVID-19-associated hospitalization

55%95% CI: 41%-66%Source [26]
All 4 findings from this source

Vaccine effectiveness against ED/UC encounters in adults aged 65+

48%95% CI: 37%-56%Source [26]

Vaccine effectiveness against hospitalization in adults aged 65+

53%95% CI: 37%-65%Source [26]
Browse the 29 original sourcesThe complete bibliography behind this monitor.
  1. [1]

    Wang H, Paulson KR, Pease SA, et al. Estimating excess mortality due to the COVID-19 pandemic: a systematic analysis of COVID-19-related mortality, 2020-21. Lancet. 2022;399(10334):1513-1536.

    Open original source in a new tab
  2. [2]

    APM Research Lab. The color of coronavirus: COVID-19 deaths by race and ethnicity in the U.S. Updated 2021.

    Original source link unavailable
  3. [3]

    Davis HE, McCorkell L, Vogel JM, Topol EJ. Long COVID: major findings, mechanisms and recommendations. Nature Reviews Microbiology. 2023;21(3):133-146.

    Open original source in a new tab
  4. [4]

    Polack FP, Thomas SJ, Kitchin N, et al. Safety and efficacy of the BNT162b2 mRNA Covid-19 vaccine. N Engl J Med. 2020;383(27):2603-2615.

    Open original source in a new tab
  5. [5]

    Al-Aly Z, Bowe B, Xie Y. Outcomes of SARS-CoV-2 Reinfection. Nature Medicine. 2022;28(11):2398-2405.

    Open original source in a new tab
  6. [6]

    Watson OJ, Barnsley G, Toor J, et al. Global impact of the first year of COVID-19 vaccination: a mathematical modelling study. Lancet Infectious Diseases. 2022;22(9):1293-1302.

    Open original source in a new tab
  7. [7]

    Bobrovitz N, Ware H, Ma X, et al. Protective effectiveness of previous SARS-CoV-2 infection and hybrid immunity against the omicron variant and severe disease. Lancet Infectious Diseases. 2023;23(5):556-567.

    Open original source in a new tab
  8. [8]

    Chalkias S, Harper C, Vrbicky K, et al. A Bivalent Omicron-Containing Booster Vaccine against Covid-19. N Engl J Med. 2022;387(14):1279-1291.

    Open original source in a new tab
  9. [9]

    Feikin DR, Higdon MM, Abu-Raddad LJ, et al. Duration of effectiveness of vaccines against SARS-CoV-2 infection and COVID-19 disease: Results of a systematic review and meta-regression. Lancet. 2022;399(10328):924-944.

    Open original source in a new tab
  10. [10]

    Brauner JM, Mindermann S, Sharma M, et al. Inferring the effectiveness of government interventions against COVID-19. Science. 2021;371(6531):eabd9338.

    Open original source in a new tab
  11. [11]

    Flaxman S, Mishra S, Gandy A, et al. Estimating the effects of non-pharmaceutical interventions on COVID-19 in Europe. Nature. 2020;584(7820):257-261.

    Open original source in a new tab
  12. [12]

    PHOSP-COVID Collaborative Group. Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK. Lancet Respiratory Medicine. 2022;10(8):761-775.

    Open original source in a new tab
  13. [13]

    Chen C, Haupert SR, Zimmermann L, Shi X, Fritsche LG, Mukherjee B. Global prevalence of post-COVID-19 condition or long COVID: A meta-analysis and systematic review. J Infect Dis. 2022;226(9):1593-1607.

    Open original source in a new tab
  14. [14]

    Bilal U, Tabb LP, Engel SM, et al. Racial/ethnic and neighborhood disparities in COVID-19 in the United States. Ann Intern Med. 2021;174(6):840-843.

    Open original source in a new tab
  15. [15]

    Arrazola J, Masiello MM, Joshi S, et al. COVID-19 mortality among American Indian and Alaska Native persons - 14 States, January-June 2020. MMWR Morb Mortal Wkly Rep. 2020;69(49):1853-1856.

    Open original source in a new tab
  16. [16]

    COVID-19 Mental Disorders Collaborators. Global prevalence and burden of depressive and anxiety disorders in 204 countries and territories in 2020 due to the COVID-19 pandemic. Lancet. 2021;398(10312):1700-1712.

    Open original source in a new tab
  17. [17]

    Cutler DM, Summers LH. The COVID-19 pandemic and the $16 trillion virus. JAMA. 2020;324(15):1495-1496.

    Open original source in a new tab
  18. [18]

    Shanafelt TD, West CP, Dyrbye LN, et al. Changes in burnout and satisfaction with work-life integration in physicians and the general US working population between 2011 and 2020. Mayo Clin Proc. 2022;97(3):491-506.

    Open original source in a new tab
  19. [19]

    Notarte KI, Catahay JA, Velasco JV, et al. Impact of COVID-19 vaccination on the risk of developing long-COVID and on existing long-COVID symptoms: A systematic review. EClinicalMedicine. 2022;53:101624.

    Open original source in a new tab
  20. [20]

    Xie Y, Xu E, Bowe B, Al-Aly Z. Long-term cardiovascular outcomes of COVID-19. Nature Medicine. 2022;28(3):583-590.

    Open original source in a new tab
  21. [21]

    Xie Y, Al-Aly Z. Risks and burdens of incident diabetes in long COVID: a cohort study. Lancet Diabetes Endocrinology. 2022;10(5):311-321.

    Open original source in a new tab
  22. [22]

    Thompson MG, Stenehjem E, Grannis S, et al. Effectiveness of Covid-19 vaccines in ambulatory and inpatient care settings. N Engl J Med. 2021;385(15):1355-1371.

    Open original source in a new tab
  23. [23]

    Richardson S, Hirsch JS, Narasimhan M, et al. Presenting characteristics, comorbidities, and outcomes among 5700 patients hospitalized with COVID-19 in the New York City area. JAMA. 2020;323(20):2052-2059.

    Open original source in a new tab
  24. [24]

    Grasselli G, Zangrillo A, Zanella A, et al. Baseline characteristics and outcomes of 1591 patients infected with SARS-CoV-2 admitted to ICUs of the Lombardy Region, Italy. JAMA. 2020;323(16):1574-1581.

    Open original source in a new tab
  25. [25]

    Li, Shen et al.. Global prevalence of prolonged grief disorder during the COVID-19 pandemic under standardized diagnostic frameworks: A systematic review and meta-analysis.. Psychological medicine. 2026.

    Open original source in a new tab
  26. [26]

    Wiegand, Ryan E et al.. Interim Estimated Effectiveness of 2025-2026 COVID-19 Vaccines in Adults Using a Test-Negative Design.. JAMA network open. 2026.

    Open original source in a new tab
  27. [27]

    Sung, Gabriel Chun Yin et al.. Mental Health Symptom Changes by Sex or Gender Before and During the COVID-19 Pandemic: A Systematic Review and Meta-Analysis.. JAMA network open. 2026.

    Open original source in a new tab
  28. [28]

    Brock, Jonas et al.. Inter-hospital ICU-to-ICU transfer of critically ill COVID-19 patients is not associated with increased mortality: a systematic review with exploratory meta-analysis.. Scientific reports. 2026.

    Open original source in a new tab
  29. [29]

    Gao, Yumeng et al.. Association between psychological wellbeing and the COVID-19-related outcomes in Europeans aged ≥ 50 years old: The SHARE study.. Human vaccines & immunotherapeutics. 2026.

    Open original source in a new tab
ABOUT THIS MONITOR

Understanding includes the limits.

This is an AI-assisted evidence summary, not a clinician endorsement. Read each original paper for its complete methods, population and limitations. Different studies can ask different questions and report different kinds of results.

Dates marked “added” describe when a finding entered this monitor, not when the study was published or clinically reviewed. Personal health and treatment decisions belong in a conversation with a qualified clinician.

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