key: cord-0712660-82hiuknz
authors: Young-Xu, Yinong; Korves, Caroline; Roberts, Jeff; Powell, Ethan I.; Zwain, Gabrielle M.; Smith, Jeremy; Izurieta, Hector S.
title: Coverage and Estimated Effectiveness of mRNA COVID-19 Vaccines Among US Veterans
date: 2021-10-06
journal: JAMA Netw Open
DOI: 10.1001/jamanetworkopen.2021.28391
sha: c73ada70c28859c4175f3772e2d1a127803b99c6
doc_id: 712660
cord_uid: 82hiuknz

IMPORTANCE: Effectiveness of mRNA vaccinations in a diverse older population with high comorbidity is unknown. OBJECTIVES: To describe the scope of the COVID-19 vaccination rollout among US veterans, and to estimate mRNA COVID-19 vaccine effectiveness (VE) as measured by rates of SARS-CoV-2 infection. DESIGN, SETTING, AND PARTICIPANTS: This matched test–negative case-control study was conducted using SARS-CoV-2 test results at Veterans Health Administration sites from December 14, 2020, to March 14, 2021. Vaccine coverage was estimated for all veterans. VE against SARS-CoV-2 infection and COVID-19–related hospitalization and death were estimated using electronic health records from veterans who routinely sought care at a VHA facility and had a test result positive for SARS-CoV-2 (cases) or negative for SARS-CoV-2 (controls). Cases and controls were matched on time of test and geographic region. Data were analyzed from May to July 2021. EXPOSURES: Vaccination status, defined as unvaccinated, partially vaccinated (≥14 days after first dose until second dose), or fully vaccinated (≥14 days after second dose), at time of test. MAIN OUTCOMES AND MEASURES: The main outcome of interest was a positive result for SARS-CoV-2 on a polymerase chain reaction or antigen test. Secondary outcomes included COVID-19–related hospitalization and death, defined by discharge data and proximity of event to positive test result. VE was estimated from odds ratios for SARS-CoV-2 infection with 95% CIs. RESULTS: Among 6 647 733 veterans included (3 350 373 veterans [50%] aged ≥65 years; 6 014 798 [90%] men and 632 935 [10%] women; 461 645 Hispanic veterans of any race [7%], 1 102 471 non-Hispanic Black veterans [17%], and 4 361 621 non-Hispanic White veterans [66%]), 1 363 180 (21%) received at least 1 COVID-19 vaccination by March 7, 2021. In this period, during which the share of SARS-CoV-2 variants Alpha, Epsilon, and Iota had started to increase in the US, estimates of COVID-19 VE against infection, regardless of symptoms, was 95% (95% CI, 93%-96%) for full vaccination and 64% (95% CI, 59%-68%) for partial vaccination. Estimated VE against COVID-19–related hospitalization for full vaccination was 91% (95% CI 83%-95%); there were no deaths among veterans who were fully vaccinated. VE against infection was similar across subpopulations (non-Hispanic Black, 94% [95% CI, 88%-97%]; Hispanic [any race], 83% [95% CI, 45%-95%]; non-Hispanic White, 92% [95% CI 88%-94%]; rural, 94% [95% CI, 89%-96%]; urban, 93% 95% CI, 89%-95%]). CONCLUSIONS AND RELEVANCE: For veterans of all racial and ethnic subgroups living in urban or rural areas, mRNA vaccination was associated with substantially decreased risk of COVID-19 infection and hospitalization, with no deaths among fully vaccinated veterans.

Age Integer Age as of the specimen collection date for SARS-CoV-2 lab test Asthma 0/1 ICD-10 code J45* ICD-10 code J44.9* ICD-10 code J67.8* Cancer 0/1 Charlson condition definitions using ICD-10 codes Cancer metastatic 0/1 Charlson condition definitions using ICD-10 codes Coronary artery disease 0/1 ICD-10 code I 25* Congestive heart failure 0/1 Charlson condition definitions using ICD-10 codes Chronic kidney disease 0/1 ICD-10 code N18* Chronic obstructive pulmonary disease 0/1 Charlson condition definitions using ICD-10 codes Cardiovascular disease 0/1 Charlson condition definitions using ICD-10 codes Dementia 0/1 Charlson condition definitions using ICD-10 codes Diabetes mellitus with complications 0/1 Charlson condition definitions using ICD-10 codes Diabetes mellitus without complications 0/1 Charlson condition definitions using ICD-10 codes Dyslipidemia 0/1 ICD-10 code E78.5* HIV 0/1 Charlson condition definitions using ICD-10 codes Hypertension 0/1 ICD-10 code H35.03 ICD-10 code I10* ICD-10 code I11* ICD-10 code I12* ICD-10 code I13* ICD-10 code I15* ICD-10 code I16 ICD-10 code I67.4 Liver disease, mild 0/1 Charlson condition definitions using ICD-10 codes Liver disease, severe 0/1 Charlson condition definitions using ICD-10 codes Myocardial infarction (history) 0/1 Charlson condition definitions using ICD-10 codes Para/hemiplegia 0/1 Charlson condition definitions using ICD-10 codes Peptic ulcer disease 0/1 Charlson condition definitions using ICD-10 codes Peripheral vascular disease 0/1 Charlson condition definitions using ICD-10 codes Rheumatoid arthritis 0/1 Charlson condition definitions using ICD-10 codes Renal disease 0/1 Charlson condition definitions using ICD-10 codes Atrial fibrillation 0/1 ICD-10 code I48.0 ICD-10 code I48.11 ICD-10 code I48.19 ICD-10 code I48.21 ICD-10 code I48.91 Anaphylaxis (history) 0/1 ICD-10 code Z87.892

Arthritis 0/1 ICD-10 code M15* through M19* Bleeding diathesis 0/1 ICD-10 code D69.9

Bronchiectasis 0/1 ICD-10 code J47* Depression 0/1 ICD-10 code F33* Down Syndrome 0/1 ICD-10 code Q90* Embolism (history) 0/1 ICD-10 code I82* ICD-10 code I74* ICD-10 code I26* Falls (history) 0/1 ICD-10 code W19* Immunocompromised 0/1 ICD-10 code B20* ICD-10 code B59* ICD-10 code B97.3* ICD-10 code D47.Z1* ICD-10 code D70* ICD-10 code D71* ICD-10 code D72* ICD-10 code D73* ICD-10 code D76* ICD-10 code D80* ICD-10 code D81* ICD-10 code D82* ICD-10 code D83* ICD-10 code D84* ICD-10 code D89* ICD-10 code M05* ICD-10 code M06* ICD-10 code M07* ICD-10 code M08* ICD-10 code M30* ICD-10 code M31* ICD-10 code M32* ICD-10 code M33* ICD-10 code M34* ICD-10 code M35.0* ICD-10 code M35.9* ICD-10 code Q89.0* ICD-10 code T45.1X1 ICD-10 code Z21* ICD-10 code Z48.2* ICD-10 code Z51.0* ICD-10 code Z51. 

% (95%CI) Full vs. no vaccination Partial vs. no vaccination Unadjusted Adjusted c Unadjusted Adjusted c Overall 96 (95, 97) 95 (93, 96) 71 (67, 75) 59 (52, 65) Age, y 18-64 91

55) Underlying medical conditions Cancer 82 (66, 91) 84 (70, 92) 53 (32, 68) 56 (36, 70) Congestive heart failure 87 (76, 92) 89 (80, 94) 64 (50, 74) 66 (52, 75) Chronic kidney disease 89

Abbreviations: BMI, body mass index

COVID-19"] diagnosis code in inpatient, skilled nursing facility, institutional outpatient, hospice, and carrier/Part B files), the VHA receives the patients' Medicare data with a 4-5 week lag time

The adjusted variables include the following: age, BMI, cancer, congestive heart failure, chronic kidney disease, diabetes mellitus, hypertension, immunocompromised, VA priority level, race/ethnicity, sex, rurality

% (95%CI) Full vs. no vaccination Partial vs. no vaccination Unadjusted Adjusted b Unadjusted Adjusted b PCR test 96 (94, 97) 93 (90, 95) 71 (67, 74) 59 (53, 64) Antigen test 96

Abbreviations: BMI, body mass index

The adjusted variables include the following: age, BMI, cancer, congestive heart failure, chronic kidney disease, diabetes mellitus, hypertension, immunocompromised, VA priority level, race/ethnicity, sex

Part v. None: 2,532 a A breakdown by full and partial vaccination status would violate federal cell size suppression policy. b The number of cases and controls were different for the matched analysis for VE for full and partial vaccination.