The potential contributions of bouillon fortification to meeting micronutrient requirements among women and preschool children in Senegal: A modeling study using household consumption and expenditure survey data.

To reduce micronutrient deficiencies, Senegal mandates the fortification of refined oil with vitamin A and wheat flour with iron and folic acid. Expanding Senegal's large-scale food fortification programs to include fortified bouillon could help fill the remaining gaps in dietary micronutrient requirements. Using 7-day household food consumption data collected between 2018 and 2019, we assessed the potential contributions of bouillon fortified with vitamin A (40-250 µg/g bouillon), folic acid (20-120 µg/g), vitamin B12 (0.2-2 µg/g), iron (0.6-5 mg/g), and zinc (0.6-5 mg/g) for meeting micronutrient requirements of women of reproductive age (WRA; 15-49 years old) and children (6-59 months old). Most households (90%) reported consuming bouillon, including poor and rural households. At modeled fortification levels, bouillon fortification reduced the national prevalence of inadequacy by up to ∼20 percentage points (pp) for vitamin A, 34 pp (WRA) and 20 pp (children) for folate, 20 pp for vitamin B12, 38 pp (WRA) and 30 pp (children) for zinc, and ∼8 pp for iron. Predicted reductions in inadequacy were generally larger among poor and rural populations, especially for vitamins A and B12. Our modeling suggests that bouillon fortification has the potential to substantially reduce dietary inadequacy of multiple micronutrients and could also help address inequities in dietary micronutrient inadequacies in Senegal.

Influenza Vaccine Effectiveness Against Influenza A-Associated Emergency Department, Urgent Care, and Hospitalization Encounters Among US Adults, 2022-2023.

BACKGROUND: The 2022-2023 United States influenza season had unusually early influenza activity with high hospitalization rates. Vaccine-matched A(H3N2) viruses predominated, with lower levels of A(H1N1)pdm09 activity also observed. METHODS: Using the test-negative design, we evaluated influenza vaccine effectiveness (VE) during the 2022-2023 season against influenza A-associated emergency department/urgent care (ED/UC) visits and hospitalizations from October 2022 to March 2023 among adults (aged ≥18 years) with acute respiratory illness (ARI). VE was estimated by comparing odds of seasonal influenza vaccination among case-patients (influenza A test positive by molecular assay) and controls (influenza test negative), applying inverse-propensity-to-be-vaccinated weights. RESULTS: The analysis included 85 389 ED/UC ARI encounters (17.0% influenza A positive; 37.8% vaccinated overall) and 19 751 hospitalizations (9.5% influenza A positive; 52.8% vaccinated overall). VE against influenza A-associated ED/UC encounters was 44% (95% confidence interval [CI], 40%-47%) overall and 45% and 41% among adults aged 18-64 and ≥65 years, respectively. VE against influenza A-associated hospitalizations was 35% (95% CI, 27%-43%) overall and 23% and 41% among adults aged 18-64 and ≥65 years, respectively. CONCLUSIONS: VE was moderate during the 2022-2023 influenza season, a season characterized with increased burden of influenza and co-circulation with other respiratory viruses. Vaccination is likely to substantially reduce morbidity, mortality, and strain on healthcare resources.

Modeling the Contribution of Multiple Micronutrient Fortification of Salt to Daily Nutrient Intake Among the Ethiopian Population.

Background: Salt is an affordable commodity and has wide coverage regardless of economic and social status and, hence, could be suitable vehicle for multiple micronutrient fortification. Objectives: This study aimed to simulate the contribution folic acid and zinc fortification of iodized salt to nutrient intake among the Ethiopian population. Methods: The 2013 Ethiopian National Food Consumption Survey and various food composition tables were used to estimate baseline individual-level micronutrient intake. Usual intake was estimated using the Simulating Intake of Micronutrients for Policy Learning and Engagement macro tool. Discretionary salt consumption was calculated from total salt intake estimated using urinary sodium excretion. Fortificant addition rates were set to obtain maximum nutrient intake while simultaneously constraining that population with intake above the tolerable upper intake level to <5%. Addis Ababa and Somali (N = 2271), the regions with relatively the lowest and highest micronutrient deficiency prevalence in Ethiopia, were selected. Result: Baseline median intake of Zn was below the estimated average requirement for all demographic groups. Inadequate Zn intake ranged from 73% to 99%, the highest prevalence being observed among women in lower class of wealth quintiles from Somali region. Dietary folate inadequacy was as low as 2% among men in Addis Ababa but almost all (99%) women from Somali region had inadequate folate intake. Calculated discretionary salt intake was 7.5 g/d for adult men and women and 3.4 g/d for children. With addition 0.8 mg Zn and 30 µg of folic acid per gram of salt, multiple salt fortification is estimated to reduce Zn inadequacy by 38 percentage points in urban areas and19 percentage points in rural areas. Modeled reduction in folate inadequacy were 18% in urban areas and 22% in rural areas. Conclusions: Multiple salt fortification could be an effective approach to address micronutrient adequacy in Ethiopia given efficacious, technological, and economical feasibility.

Modeled impacts of bouillon fortification with micronutrients on child mortality in Senegal, Burkina Faso, and Nigeria.

Micronutrient interventions can reduce child mortality. By applying Micronutrient Intervention Modeling methods in Senegal, Burkina Faso, and Nigeria, we estimated the impacts of bouillon fortification on apparent dietary adequacy of vitamin A and zinc among children and folate among women. We then used the Lives Saved Tool to predict the impacts of bouillon fortification with ranges of vitamin A, zinc, and folic acid concentrations on lives saved among children 6-59 months of age. Fortification at 250 µg vitamin A/g and 120 µg folic acid/g was predicted to substantially reduce vitamin A- and folate-attributable deaths: 65% for vitamin A and 92% for folate (Senegal), 36% for vitamin A and 74% for folate (Burkina Faso), and >95% for both (Nigeria). Zinc fortification at 5 mg/g would avert 48% (Senegal), 31% (Burkina Faso), and 63% (Nigeria) of zinc-attributable deaths. The addition of all three nutrients at 30% of Codex nutrient reference values in 2.5 g bouillon was predicted to save an annual average of 293 child lives in Senegal (3.5% of deaths from all causes among children 6-59 months of age), 933 (2.1%) in Burkina Faso, and 18,362 (3.7%) in Nigeria. These results, along with evidence on program feasibility and costs, can help inform fortification program design discussions.

Effect of multiple micronutrient-fortified bouillon on micronutrient status among women and children in the Northern Region of Ghana: Protocol for the Condiment Micronutrient Innovation Trial (CoMIT), a community-based randomized controlled trial.

INTRODUCTION: Micronutrient deficiencies are prevalent in West Africa, particularly among women of reproductive age (WRA) and young children. Bouillon is a promising food fortification vehicle due to its widespread consumption. This study aims to evaluate the impact of multiple micronutrient-fortified bouillon cubes, compared to control bouillon cubes (fortified with iodine only), on micronutrient status and hemoglobin concentrations among lactating and non-lactating WRA and young children in northern Ghana. METHODS: This randomized, controlled doubly-masked trial will be conducted in the Kumbungu and Tolon districts in the Northern Region of Ghana, where prior data indicate multiple micronutrient deficiencies are common. Participants will be: 1) non-pregnant non-lactating WRA (15-49 y), 2) children 2-5 y, and 3) non-pregnant lactating women 4-18 months postpartum. Eligible participants will be randomly assigned to receive household rations of one of two types of bouillon cubes: 1) a multiple micronutrient-fortified bouillon cube containing vitamin A, folic acid, vitamin B12, iron, zinc, and iodine, or 2) a control cube containing iodine only. Each participant's household will receive a ration of bouillon cubes every 2 weeks, and households will be advised to prepare meals as usual, using the study-provided cubes. The trial duration will be 9 months for non-pregnant non-lactating WRA and children, and 3 months for lactating women. The primary outcomes will be changes in biomarkers of micronutrient status and hemoglobin among WRA and children and milk micronutrient concentrations among lactating women. Secondary outcomes will include change in prevalence of micronutrient deficiency and anemia; dietary intake of bouillon and micronutrients; inflammation, malaria, and morbidity symptoms; and child growth and development. DISCUSSION: Evidence from this study will inform discussions about bouillon fortification in Ghana and West Africa. TRIAL REGISTRATION: The trial was registered on ClinicalTrials.gov (NCT05178407) and the Pan-African Clinical Trial Registry (PACTR202206868437931). This manuscript reflects protocol version 4 (August 29, 2022).

Micronutrient-fortified bouillon as a strategy to improve the micronutrient adequacy of diets in Burkina Faso.

Bouillon is a promising candidate for fortification to complement existing large-scale food fortification (LSFF) programs. We used household dietary data from Burkina Faso to model potential contributions of bouillon fortified with vitamin A (40-250 µg/g bouillon), folic acid (20-120 µg/g), vitamin B12 (0.2-2 µg/g), iron (0.6-5 mg/g), and zinc (0.6-5 mg/g) for meeting micronutrient requirements of women of reproductive age (15-49 years; WRA) and children (6-59 months). Most households (82%) reported bouillon consumption, with higher proportions of resource-constrained (84-88%) and rural households (88%) consuming bouillon. Accounting for the contributions of existing LSFF, household diets were inadequate to meet the micronutrient requirements of many WRA and children, exceeding 90% and 60% inadequacy for vitamins A and B12, respectively. Modeling results showed bouillon fortification could reduce inadequacy by up to ∼30 percentage points (pp) for vitamin A, ∼26 pp for folate among WRA (∼11 pp among children), ∼38 pp for vitamin B12, and 11-13 pp for zinc, with comparable reductions across socioeconomic strata and urban and rural residence. Predicted reductions in iron inadequacy were <3 pp. These results suggest dietary micronutrient inadequacies are a concern in Burkina Faso, and fortified bouillon can make substantial contributions to reducing micronutrient inadequacies, including among resource-constrained and rural populations.

Interim Estimates of 2023-24 Seasonal Influenza Vaccine Effectiveness - United States.

In the United States, annual influenza vaccination is recommended for all persons aged ≥6 months. Using data from four vaccine effectiveness (VE) networks during the 2023-24 influenza season, interim influenza VE was estimated among patients aged ≥6 months with acute respiratory illness-associated medical encounters using a test-negative case-control study design. Among children and adolescents aged 6 months-17 years, VE against influenza-associated outpatient visits ranged from 59% to 67% and against influenza-associated hospitalization ranged from 52% to 61%. Among adults aged ≥18 years, VE against influenza-associated outpatient visits ranged from 33% to 49% and against hospitalization from 41% to 44%. VE against influenza A ranged from 46% to 59% for children and adolescents and from 27% to 46% for adults across settings. VE against influenza B ranged from 64% to 89% for pediatric patients in outpatient settings and from 60% to 78% for all adults across settings. These findings demonstrate that the 2023-24 seasonal influenza vaccine is effective at reducing the risk for medically attended influenza virus infection. CDC recommends that all persons aged ≥6 months who have not yet been vaccinated this season get vaccinated while influenza circulates locally.

Acceptability of Multiple Micronutrient-Fortified Bouillon Cubes among Women and Their Households in 2 Districts in The Northern Region of Ghana.

Background: Bouillon is a promising large-scale food fortification vehicle, but there is uncertainty regarding the types and concentrations of micronutrients that are feasible to add without compromising consumer acceptability. Objective: The objective of this study was to evaluate the acceptability of 2 different multiple micronutrient-fortified bouillon cube formulations, compared with a bouillon cube fortified with iodine only. Methods: We conducted a double-blind, randomized, controlled acceptability study in 2 districts in northern Ghana. Two nonproprietary, noncommercialized formulations of multiple micronutrient-fortified bouillon cubes containing iron, zinc, folic acid, vitamins A and B12, and iodine at "upper-level" (45-125% CODEX NRV/2.5g) or "lower-level" (15-50% CODEX NRV/2.5g) concentrations, and a control cube that contained iodine only (50% CODEX NRV/2.5g) were evaluated. Eligible women (n = 84) were invited to participate in 1) center-based sensory evaluations designed to permit within-individual comparisons among the different study products; and 2) in-home evaluation of bouillon acceptability and use, in which participants were randomized to receive 1 of the 3 study products to use in household cooking for a 2-wk period. Acceptance test ratings were based on a 5-point Likert scale (1 = dislike very much, 5 = like very much). Results: In the center-based evaluations, overall liking of the 3 bouillon cube formulations both dry and in prepared dishes ranged from 4.3 to 4.6 on the 5-point Likert scale and did not differ among formulations (P > 0.05). After the 2-wk in-home trial, 93.8% of index participants (n = 75/80) rated their overall liking of the bouillon product formulation to which they were randomly assigned as "like" or "like very much" (4-5 on the 5-point Likert scale) and median apparent intake of study-provided bouillon over 2 wk was 3.6 g/capita/d; neither value differed by study group (P = 0.91 for both). Conclusions: All 3 formulations of bouillon cubes assessed were acceptable to women and their households in 2 districts in northern Ghana.This trial was registered at www.clinicaltrials.gov as NCT05177614.

Consumption of Discretionary Salt and Salt from Bouillon among Households, Women, and Young Children in Northern Region, Ghana: A Mixed-Methods Study with the Condiment Micronutrient Innovation Trial (CoMIT) Project.

Background: Information on salt consumption patterns is needed to inform the need for and design of salt reduction strategies. Objectives: In northern Ghana, this study aimed to estimate household consumption of salt, including salt from bouillon, and compare (estimated) women and children's salt intake to global recommendations; to estimate the proportion of salt consumed from bouillon; and to identify factors, including knowledge, attitudes, and practices, associated with household salt consumption. Methods: Employing mixed-methods methodology, we conducted a pilot survey (n = 369 households enrolled) and focus group discussions (FGDs; n = 20) in Tolon and Kumbungu districts (14 urban, 14 rural clusters) (clinicaltrials.gov registry: NCT04632771). Households reported purchases of discretionary salt (DS, "table salt") and bouillon cubes. DS and total salt (TS; DS+salt from bouillon) consumption for women (15-49 y) and children (2-5 y) were estimated using the Adult Male Equivalent method and compared with global recommendations (<5 g/d women; <3.75 g/d children). Women's salt intake was also predicted from urinary sodium excretion (INTERSALT equation). Associations between DS and TS consumption, as well as household and women's characteristics, were tested with minimally adjusted and multivariable linear mixed-effects models. Qualitative FGD themes were generated using the Framework Method. Results: From household purchase data, estimated TS consumption exceeded global recommendations for 44% of children [median: 2.9 (IQR: 1.9, 5.2) g/d] and 60% of women [6.0 (4.0, 10.2) g/d]; 35% of children and 50% of women exceeded recommendations from DS alone. Bouillon contributed <25% of households' TS consumption. Few characteristics were associated with DS or TS consumption. Salient qualitative themes that shaped salt consumption behaviors included salt's ubiquity as a seasoning, key household members' influence on food procurement and preparation, and perceptions about health. Conclusions: Purchase data suggest salt consumption among women and children exceeds recommendations, even when excluding salt from bouillon; food prepared outside the home likely further contributes. Salt reduction interventions may be warranted in this context.

Estimating minimum dietary diversity for children aged 6-23 months: a comparison of agreement and cost of two recall methods in Cambodia and Zambia.

OBJECTIVE: To compare the agreement and cost of two recall methods for estimating children's minimum dietary diversity (MDD). DESIGN: We assessed child's dietary intake on two consecutive days: an observation on day one, followed by two recall methods (list-based recall and multiple-pass recall) administered in random order by different enumerators at two different times on day two. We compared the estimated MDD prevalence using survey-weighted linear probability models following a two one-sided test equivalence testing approach. We also estimated the cost-effectiveness of the two methods. SETTING: Cambodia (Kampong Thom, Siem Reap, Battambang, and Pursat provinces) and Zambia (Chipata, Katete, Lundazi, Nyimba, and Petauke districts). PARTICIPANTS: Children aged 6-23 months: 636 in Cambodia and 608 in Zambia. RESULTS: MDD estimations from both recall methods were equivalent to the observation in Cambodia but not in Zambia. Both methods were equivalent to the observation in capturing most food groups. Both methods were highly sensitive although the multiple-pass method accurately classified a higher proportion of children meeting MDD than the list-based method in both countries. Both methods were highly specific in Cambodia but moderately so in Zambia. Cost-effectiveness was better for the list-based recall method in both countries. CONCLUSION: The two recall methods estimated MDD and most other infant and young child feeding indicators equivalently in Cambodia but not in Zambia, compared to the observation. The list-based method produced slightly more accurate estimates of MDD at the population level, took less time to administer and was less costly to implement.

Clinical Epidemiology and Risk Factors for Critical Outcomes Among Vaccinated and Unvaccinated Adults Hospitalized With COVID-19-VISION Network, 10 States, June 2021-March 2023.

BACKGROUND: The epidemiology of coronavirus disease 2019 (COVID-19) continues to develop with emerging variants, expanding population-level immunity, and advances in clinical care. We describe changes in the clinical epidemiology of COVID-19 hospitalizations and risk factors for critical outcomes over time. METHODS: We included adults aged ≥18 years from 10 states hospitalized with COVID-19 June 2021-March 2023. We evaluated changes in demographics, clinical characteristics, and critical outcomes (intensive care unit admission and/or death) and evaluated critical outcomes risk factors (risk ratios [RRs]), stratified by COVID-19 vaccination status. RESULTS: A total of 60 488 COVID-19-associated hospitalizations were included in the analysis. Among those hospitalized, median age increased from 60 to 75 years, proportion vaccinated increased from 18.2% to 70.1%, and critical outcomes declined from 24.8% to 19.4% (all P < .001) between the Delta (June-December, 2021) and post-BA.4/BA.5 (September 2022-March 2023) periods. Hospitalization events with critical outcomes had a higher proportion of ≥4 categories of medical condition categories assessed (32.8%) compared to all hospitalizations (23.0%). Critical outcome risk factors were similar for unvaccinated and vaccinated populations; presence of ≥4 medical condition categories was most strongly associated with risk of critical outcomes regardless of vaccine status (unvaccinated: adjusted RR, 2.27 [95% confidence interval {CI}, 2.14-2.41]; vaccinated: adjusted RR, 1.73 [95% CI, 1.56-1.92]) across periods. CONCLUSIONS: The proportion of adults hospitalized with COVID-19 who experienced critical outcomes decreased with time, and median patient age increased with time. Multimorbidity was most strongly associated with critical outcomes.

Vaccine Effectiveness Against Pediatric Influenza-A-Associated Urgent Care, Emergency Department, and Hospital Encounters During the 2022-2023 Season: VISION Network.

BACKGROUND: During the 2022-2023 influenza season, the United States experienced the highest influenza-associated pediatric hospitalization rate since 2010-2011. Influenza A/H3N2 infections were predominant. METHODS: We analyzed acute respiratory illness (ARI)-associated emergency department or urgent care (ED/UC) encounters or hospitalizations at 3 health systems among children and adolescents aged 6 months-17 years who had influenza molecular testing during October 2022-March 2023. We estimated influenza A vaccine effectiveness (VE) using a test-negative approach. The odds of vaccination among influenza-A-positive cases and influenza-negative controls were compared after adjusting for confounders and applying inverse-propensity-to-be-vaccinated weights. We developed overall and age-stratified VE models. RESULTS: Overall, 13 547 of 44 787 (30.2%) eligible ED/UC encounters and 263 of 1862 (14.1%) hospitalizations were influenza-A-positive cases. Among ED/UC patients, 15.2% of influenza-positive versus 27.1% of influenza-negative patients were vaccinated; VE was 48% (95% confidence interval [CI], 44-52%) overall, 53% (95% CI, 47-58%) among children aged 6 months-4 years, and 38% (95% CI, 30-45%) among those aged 9-17 years. Among hospitalizations, 17.5% of influenza-positive versus 33.4% of influenza-negative patients were vaccinated; VE was 40% (95% CI, 6-61%) overall, 56% (95% CI, 23-75%) among children ages 6 months-4 years, and 46% (95% CI, 2-70%) among those 5-17 years. CONCLUSIONS: During the 2022-2023 influenza season, vaccination reduced the risk of influenza-associated ED/UC encounters and hospitalizations by almost half (overall VE, 40-48%). Influenza vaccination is a critical tool to prevent moderate-to-severe influenza illness in children and adolescents.

Influenza vaccine effectiveness against influenza-A-associated emergency department, urgent care, and hospitalization encounters among U.S. adults, 2022-2023.

BACKGROUND: The 2022-2023 United States influenza season had unusually early influenza activity with high hospitalization rates. Vaccine-matched A(H3N2) viruses predominated, with lower levels of A(H1N1)pdm09 activity also observed. METHODS: Using the test-negative design, we evaluated influenza vaccine effectiveness (VE) during the 2022-2023 season against influenza-A-associated emergency department/urgent care (ED/UC) visits and hospitalizations from October 2022-March 2023 among adults (age ≥18 years) with acute respiratory illness (ARI). VE was estimated by comparing odds of seasonal influenza vaccination among case-patients (influenza A test-positive by molecular assay) and controls (influenza test-negative), applying inverse-propensity-to-be-vaccinated weights. RESULTS: The analysis included 85,389 ED/UC ARI encounters (17.0% influenza-A-positive; 37.8% vaccinated overall) and 19,751 hospitalizations (9.5% influenza-A-positive; 52.8% vaccinated overall). VE against influenza-A-associated ED/UC encounters was 44% (95% confidence interval [95%CI]: 40-47%) overall and 45% and 41% among adults aged 18-64 and ≥65 years, respectively. VE against influenza-A-associated hospitalizations was 35% (95%CI: 27-43%) overall and 23% and 41% among adults aged 18-64 and ≥65 years, respectively. CONCLUSIONS: VE was moderate during the 2022-2023 influenza season, a season characterized with increased burden of influenza and co-circulation with other respiratory viruses. Vaccination is likely to substantially reduce morbidity, mortality, and strain on healthcare resources.

Effectiveness of the Original Monovalent Coronavirus Disease 2019 Vaccines in Preventing Emergency Department or Urgent Care Encounters and Hospitalizations Among Adults With Disabilities: VISION Network, June 2021-September 2022.

Adults with disabilities are at increased risk for severe coronavirus disease 2019 (COVID-19). Using data across 9 states during Delta- and Omicron-predominant periods (June 2021-September 2022), we evaluated the effectiveness of the original monovalent COVID-19 messenger RNA vaccines among 521 206 emergency department/urgent care encounters (11 471 [2%] in patients with a documented disability) and 139 548 hospitalizations (16 569 [12%] in patients with a disability) for laboratory-confirmed COVID-19 illness in adults (aged ≥18 years). Across variant periods and for the primary series or booster doses, vaccine effectiveness was similar in those with and those without a disability. These findings highlight the importance of adults with disabilities staying up to date with COVID-19 vaccinations.

The cost-effectiveness of small-quantity lipid-based nutrient supplements for prevention of child death and malnutrition and promotion of healthy development: modelling results for Uganda.

OBJECTIVE: Recent meta-analyses demonstrate that small-quantity lipid-based nutrient supplements (SQ-LNS) for young children significantly reduce child mortality, stunting, wasting, anaemia and adverse developmental outcomes. Cost considerations should inform policy decisions. We developed a modelling framework to estimate the cost and cost-effectiveness of SQ-LNS and applied the framework in the context of rural Uganda. DESIGN: We adapted costs from a costing study of micronutrient powder (MNP) in Uganda, and based effectiveness estimates on recent meta-analyses and Uganda-specific estimates of baseline mortality and the prevalence of stunting, wasting, anaemia and developmental disability. SETTING: Rural Uganda. PARTICIPANTS: Not applicable. RESULTS: Providing SQ-LNS daily to all children in rural Uganda (> 1 million) for 12 months (from 6 to 18 months of age) via the existing Village Health Team system would cost ∼$52 per child (2020 US dollars) or ∼$58·7 million annually. SQ-LNS could avert an average of > 242 000 disability-adjusted life years (DALYs) annually as a result of preventing 3689 deaths, > 160 000 cases of moderate or severe anaemia and ∼6000 cases of developmental disability. The estimated cost per DALY averted is $242. CONCLUSIONS: In this context, SQ-LNS may be more cost-effective than other options such as MNP or the provision of complementary food, although the total cost for a programme including all age-eligible children would be high. Strategies to reduce costs, such as targeting to the most vulnerable populations and the elimination of taxes on SQ-LNS, may enhance financial feasibility.

Number needed to vaccinate with a COVID-19 booster to prevent a COVID-19-associated hospitalization during SARS-CoV-2 Omicron BA.1 variant predominance, December 2021-February 2022, VISION Network: a retrospective cohort study.

Background: Understanding the usefulness of additional COVID-19 vaccine doses-particularly given varying disease incidence-is needed to support public health policy. We characterize the benefits of COVID-19 booster doses using number needed to vaccinate (NNV) to prevent one COVID-19-associated hospitalization or emergency department encounter. Methods: We conducted a retrospective cohort study of immunocompetent adults at five health systems in four U.S. states during SARS-CoV-2 Omicron BA.1 predominance (December 2021-February 2022). Included patients completed a primary mRNA COVID-19 vaccine series and were either eligible to or received a booster dose. NNV were estimated using hazard ratios for each outcome (hospitalization and emergency department encounters), with results stratified by three 25-day periods and site. Findings: 1,285,032 patients contributed 938 hospitalizations and 2076 emergency department encounters. 555,729 (43.2%) patients were aged 18-49 years, 363,299 (28.3%) 50-64 years, and 366,004 (28.5%) ≥65 years. Most patients were female (n = 765,728, 59.6%), White (n = 990,224, 77.1%), and non-Hispanic (n = 1,063,964, 82.8%). 37.2% of patients received a booster and 62.8% received only two doses. Median estimated NNV to prevent one hospitalization was 205 (range 44-615) and NNV was lower across study periods for adults aged ≥65 years (110, 46, and 88, respectively) and those with underlying medical conditions (163, 69, and 131, respectively). Median estimated NNV to prevent one emergency department encounter was 156 (range 75-592). Interpretation: The number of patients needed to receive a booster dose was highly dependent on local disease incidence, outcome severity, and patient risk factors for moderate-to-severe disease. Funding: Funding was provided by the Centers for Disease Control and Prevention though contract 75D30120C07986 to Westat, Inc. and contract 75D30120C07765 to Kaiser Foundation Hospitals.

Comparison of mRNA vaccine effectiveness against COVID-19-associated hospitalization by vaccination source: Immunization information systems, electronic medical records, and self-report-IVY Network, February 1-August 31, 2022.

BACKGROUND: Accurate determination of COVID-19 vaccination status is necessary to produce reliable COVID-19 vaccine effectiveness (VE) estimates. Data comparing differences in COVID-19 VE by vaccination sources (i.e., immunization information systems [IIS], electronic medical records [EMR], and self-report) are limited. We compared the number of mRNA COVID-19 vaccine doses identified by each of these sources to assess agreement as well as differences in VE estimates using vaccination data from each individual source and vaccination data adjudicated from all sources combined. METHODS: Adults aged ≥18 years who were hospitalized with COVID-like illness at 21 hospitals in 18 U.S. states participating in the IVY Network during February 1-August 31, 2022, were enrolled. Numbers of COVID-19 vaccine doses identified by IIS, EMR, and self-report were compared in kappa agreement analyses. Effectiveness of mRNA COVID-19 vaccines against COVID-19-associated hospitalization was estimated using multivariable logistic regression models to compare the odds of COVID-19 vaccination between SARS-CoV-2-positive case-patients and SARS-CoV-2-negative control-patients. VE was estimated using each source of vaccination data separately and all sources combined. RESULTS: A total of 4499 patients were included. Patients with ≥1 mRNA COVID-19 vaccine dose were identified most frequently by self-report (n = 3570, 79 %), followed by IIS (n = 3272, 73 %) and EMR (n = 3057, 68 %). Agreement was highest between IIS and self-report for 4 doses with a kappa of 0.77 (95 % CI = 0.73-0.81). VE point estimates of 3 doses against COVID-19 hospitalization were substantially lower when using vaccination data from EMR only (VE = 31 %, 95 % CI = 16 %-43 %) than when using all sources combined (VE = 53 %, 95 % CI = 41 %-62%). CONCLUSION: Vaccination data from EMR only may substantially underestimate COVID-19 VE.

Estimates of Bivalent mRNA Vaccine Durability in Preventing COVID-19-Associated Hospitalization and Critical Illness Among Adults with and Without Immunocompromising Conditions - VISION Network, September 2022-April 2023.

On September 1, 2022, CDC's Advisory Committee on Immunization Practices (ACIP) recommended a single bivalent mRNA COVID-19 booster dose for persons aged ≥12 years who had completed at least a monovalent primary series. Early vaccine effectiveness (VE) estimates among adults aged ≥18 years showed receipt of a bivalent booster dose provided additional protection against COVID-19-associated emergency department and urgent care visits and hospitalizations compared with that in persons who had received only monovalent vaccine doses (1); however, insufficient time had elapsed since bivalent vaccine authorization to assess the durability of this protection. The VISION Network* assessed VE against COVID-19-associated hospitalizations by time since bivalent vaccine receipt during September 13, 2022-April 21, 2023, among adults aged ≥18 years with and without immunocompromising conditions. During the first 7-59 days after vaccination, compared with no vaccination, VE for receipt of a bivalent vaccine dose among adults aged ≥18 years was 62% (95% CI = 57%-67%) among adults without immunocompromising conditions and 28% (95% CI = 10%-42%) among adults with immunocompromising conditions. Among adults without immunocompromising conditions, VE declined to 24% (95% CI = 12%-33%) among those aged ≥18 years by 120-179 days after vaccination. VE was generally lower for adults with immunocompromising conditions. A bivalent booster dose provided the highest protection, and protection was sustained through at least 179 days against critical outcomes, including intensive care unit (ICU) admission or in-hospital death. These data support updated recommendations allowing additional optional bivalent COVID-19 vaccine doses for certain high-risk populations. All eligible persons should stay up to date with recommended COVID-19 vaccines.

Changing Severity and Epidemiology of Adults Hospitalized With Coronavirus Disease 2019 (COVID-19) in the United States After Introduction of COVID-19 Vaccines, March 2021-August 2022.

INTRODUCTION: Understanding the changing epidemiology of adults hospitalized with coronavirus disease 2019 (COVID-19) informs research priorities and public health policies. METHODS: Among adults (≥18 years) hospitalized with laboratory-confirmed, acute COVID-19 between 11 March 2021, and 31 August 2022 at 21 hospitals in 18 states, those hospitalized during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron-predominant period (BA.1, BA.2, BA.4/BA.5) were compared to those from earlier Alpha- and Delta-predominant periods. Demographic characteristics, biomarkers within 24 hours of admission, and outcomes, including oxygen support and death, were assessed. RESULTS: Among 9825 patients, median (interquartile range [IQR]) age was 60 years (47-72), 47% were women, and 21% non-Hispanic Black. From the Alpha-predominant period (Mar-Jul 2021; N = 1312) to the Omicron BA.4/BA.5 sublineage-predominant period (Jun-Aug 2022; N = 1307): the percentage of patients who had ≥4 categories of underlying medical conditions increased from 11% to 21%; those vaccinated with at least a primary COVID-19 vaccine series increased from 7% to 67%; those ≥75 years old increased from 11% to 33%; those who did not receive any supplemental oxygen increased from 18% to 42%. Median (IQR) highest C-reactive protein and D-dimer concentration decreased from 42.0 mg/L (9.9-122.0) to 11.5 mg/L (2.7-42.8) and 3.1 mcg/mL (0.8-640.0) to 1.0 mcg/mL (0.5-2.2), respectively. In-hospital death peaked at 12% in the Delta-predominant period and declined to 4% during the BA.4/BA.5-predominant period. CONCLUSIONS: Compared to adults hospitalized during early COVID-19 variant periods, those hospitalized during Omicron-variant COVID-19 were older, had multiple co-morbidities, were more likely to be vaccinated, and less likely to experience severe respiratory disease, systemic inflammation, coagulopathy, and death.