Length of antibiotic therapy among adults hospitalized with uncomplicated community-acquired pneumonia, 2013-2020.

Objective: The 2014 US National Strategy for Combating Antibiotic-Resistant Bacteria (CARB) aimed to reduce inappropriate inpatient antibiotic use by 20% for monitored conditions, such as community-acquired pneumonia (CAP), by 2020. We evaluated annual trends in length of therapy (LOT) in adults hospitalized with uncomplicated CAP from 2013 through 2020.

Methods: We conducted a retrospective cohort study among adults with a primary diagnosis of bacterial or unspecified pneumonia using codes in MarketScan and the Centers for Medicare & Medicaid Services databases.

Antibiotic-Resistant Infections Among Inpatients with Coronavirus Disease 2019 (COVID-19) in US Hospitals.

We described bacterial/fungal coinfections and antibiotic-resistant infections among inpatients with a diagnosis of coronavirus disease 2019 (COVID-19) and compared findings in those with a diagnosis of influenza like illness. Less than 10% of inpatients with COVID-19 had bacterial/fungal coinfection. Longer lengths of stay, critical care stay, and mechanical ventilation contribute to increased incidence of hospital-onset infections among inpatients with COVID-19.

Trends in facility-level rates of infections in US hospitals, 2019-2020.

Objectives: The coronavirus disease 2019 pandemic caused substantial changes to healthcare delivery and antibiotic prescribing beginning in March 2020. To assess pandemic impact on infection (CDI) rates, we described patients and trends in facility-level incidence, testing rates, and percent positivity during 2019-2020 in a large cohort of US hospitals.

Methods: We estimated and compared rates of community-onset CDI (CO-CDI) per 10,000 discharges, hospital-onset CDI (HO-CDI) per 10,000 patient days, and testing rates per 10,000 discharges in 2019 and 2020.

Vaccine Safety Datalink infrastructure enhancements for evaluating the safety of maternal vaccination.

Background: Identifying pregnancy episodes and accurately estimating their beginning and end dates are imperative for observational maternal vaccine safety studies using electronic health record (EHR) data.

Methods: We modified the Vaccine Safety Datalink (VSD) Pregnancy Episode Algorithm (PEA) to include both the International Classification of Disease, ninth revision (ICD-9 system) and ICD-10 diagnosis codes, incorporated additional gestational age data, and validated this enhanced algorithm with manual medical record review. We also developed the new Dynamic Pregnancy Algorithm (DPA) to identify pregnancy episodes in real time.

Evaluating the Association of Stillbirths After Maternal Vaccination in the Vaccine Safety Datalink.

Objective: To evaluate whether the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices recommended influenza and tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccinations in pregnancy are associated with increased risk of stillbirth.

Methods: We performed a case-control study in the Vaccine Safety Datalink that was matched 1:4 on site, month, and year of last menstrual period, comparing the odds of vaccination in pregnancies that ended in stillbirth (defined as fetal loss at or after 20 weeks of gestation) compared with those that ended in live birth from January 1, 2012, to September 30, 2015. We included patients with singleton pregnancies that ended in stillbirth or live birth who had at least one prenatal care visit, pregnancy dating information, and continuous health plan enrollment for the duration of pregnancy.

Bacterial Infections Associated With Substance Use Disorders, Large Cohort of United States Hospitals, 2012-2017.

Background: Rises in the incidence of bacterial infections, such as infective endocarditis (IE), have been reported in conjunction with the opioid crisis. However, recent trends for IE and other serious infections among persons with substance use disorders (SUDs) are unknown.

Methods: Using the Premier Healthcare Database, we identified hospitalizations from 2012 through 2017 among adults with primary discharge diagnoses of bacterial infections and secondary SUD diagnoses, using International Classification of Diseases, Clinical Modification Ninth and Tenth Revision codes.

Estimation of the Incidence of Guillain-Barré Syndrome During Pregnancy in the United States.

Guillain-Barré syndrome (GBS) is an adverse event of interest after vaccination, yet few data are available for background rates during pregnancy. We confirmed 2 cases of incident GBS and estimated an incidence of 2.8 confirmed GBS cases per million person-years (95% confidence interval, 0.

Association Between Estimated Cumulative Vaccine Antigen Exposure Through the First 23 Months of Life and Non-Vaccine-Targeted Infections From 24 Through 47 Months of Age.

Importance: Some parents are concerned that multiple vaccines in early childhood could weaken their child's immune system. Biological data suggest that increased vaccine antigen exposure could increase the risk for infections not targeted by vaccines.

Objective: To examine estimated cumulative vaccine antigen exposure through the first 23 months of life in children with and without non-vaccine-targeted infections from 24 through 47 months of age.

Infant Hospitalizations and Mortality After Maternal Vaccination.

Background: The Advisory Committee on Immunization Practices currently recommends pregnant women receive influenza and tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccines. There are limited studies of the long-term safety in infants for vaccines administered during pregnancy. We evaluate whether maternal receipt of influenza and Tdap vaccines increases the risk of infant hospitalization or death in the first 6 months of life.

Patterns of childhood immunization and all-cause mortality.

Background: Evidence supports the safety of the recommended childhood immunization schedule as a whole. However, additional research is warranted as parents' refusing or delaying vaccinations has increased in recent years. All-cause mortality has been identified as a priority outcome to study in the context of the recommended immunization schedule.

Maternal Tdap vaccination and risk of infant morbidity.

Introduction: An increased risk of diagnosed chorioamnionitis in women vaccinated with Tdap during pregnancy was previously detected at two Vaccine Safety Datalink (VSD) sites. The clinical significance of this finding related to infant outcomes remains uncertain.

Methods: Retrospective cohort study of singleton live births born to women who were continuously insured from 6months prior to their last menstrual period through 6weeks postpartum, with ≥1 outpatient visit during pregnancy from January 1, 2010 to November 15, 2013 at seven integrated United States health care systems part of the VSD.

Risk of Preterm or Small-for-Gestational-Age Birth After Influenza Vaccination During Pregnancy: Caveats When Conducting Retrospective Observational Studies.

Vaccines are increasingly targeted toward women of reproductive age, and vaccines to prevent influenza and pertussis are recommended during pregnancy. Prelicensure clinical trials typically have not included pregnant women, and when they are included, trials cannot detect rare events. Thus, postmarketing vaccine safety assessments are necessary.

Vaccination and 30-Day Mortality Risk in Children, Adolescents, and Young Adults.

Objective: This study evaluates the potential association of vaccination and death in the Vaccine Safety Datalink (VSD).

Methods: The study cohort included individuals ages 9 to 26 years with deaths between January 1, 2005, and December 31, 2011. We implemented a case-centered method to estimate a relative risk (RR) for death in days 0 to 30 after vaccination.

Influenza Vaccination During Pregnancy: Influenza Seasons 2002-2012, Vaccine Safety Datalink.

Introduction: Pregnant women are at risk for influenza-related complications and have been recommended for vaccination by the Advisory Committee on Immunization Practices (ACIP) since 1990. Annual rates of influenza coverage of pregnant women have been consistently low. The Vaccine Safety Datalink was used to assess influenza vaccine coverage over 10 consecutive years (2002-2012); assess patterns related to changes in ACIP recommendations; identify predictors of vaccination; and compare the results with those published by national U.

Association of Tdap Vaccination With Acute Events and Adverse Birth Outcomes Among Pregnant Women With Prior Tetanus-Containing Immunizations.

Importance: The Advisory Committee on Immunization Practices (ACIP) recommends the tetanus, diphtheria, and acellular pertussis (Tdap) vaccine for pregnant women during each pregnancy, regardless of prior immunization status. However, safety data on repeated Tdap vaccination in pregnancy is lacking.

Objective: To determine whether receipt of Tdap vaccine during pregnancy administered in close intervals from prior tetanus-containing vaccinations is associated with acute adverse events in mothers and adverse birth outcomes in neonates.

Demographic characteristics of members of the Vaccine Safety Datalink (VSD): A comparison with the United States population.

Background: The Vaccine Safety Datalink (VSD) is a collaboration between CDC and nine integrated health care systems that serves as a cornerstone of US post-licensure vaccine safety monitoring. Given concerns that potential differences between the insured VSD population and the US population could limit the generalizability of VSD study findings, we performed a comparison of the demographic characteristics between the two populations.

Methods: We collected data from medical records and administrative files at VSD sites in 2010 to compare sex, age, race, ethnicity, income, and educational attainment to the 2010 US Census population.

Childhood vaccines and Kawasaki disease, Vaccine Safety Datalink, 1996-2006.

Background: Kawasaki disease is a childhood vascular disorder of unknown etiology. Concerns have been raised about vaccinations being a potential risk factor for Kawasaki disease.

Methods: Data from the Vaccine Safety Datalink were collected on children aged 0-6 years at seven managed care organizations across the United States.

Evaluation of the association of maternal pertussis vaccination with obstetric events and birth outcomes.

Importance: In 2010, due to a pertussis outbreak and neonatal deaths, the California Department of Health recommended that the tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Tdap) be administered during pregnancy. Tdap is now recommended by the Advisory Committee on Immunization Practices for all pregnant women, preferably between 27 and 36 weeks' gestation. Limited data exist on Tdap safety during pregnancy.

Vaccinations given during pregnancy, 2002-2009: a descriptive study.

Background: A number of studies have described influenza vaccination coverage during pregnancy but few publications have described rates of other vaccinations.

Purpose: To describe vaccination rates during pregnancy in the Vaccine Safety Datalink (VSD), with particular focus on vaccinations contraindicated during pregnancy.

Methods: Pregnancies ending in 2002 through 2009 and vaccinations administered during these pregnancies were identified in the VSD.

Evaluating the safety of influenza vaccine using a claims-based health system.

Introduction: As part of the Centers for Disease Control and Prevention's monitoring and evaluation activities for influenza vaccines, we examined relationships between influenza vaccination and selected outcomes in the 2009-2010 and 2010-2011 influenza seasons in a claims-based data environment.

Methods: We included patients with claims for trivalent influenza vaccine (TIV) and/or 2009 pandemic influenza A H1N1 vaccine (H1N1) during the 2009-2010 and 2010-2011 influenza seasons. Patients were followed for several pre-specified outcomes identified in claims.

Identification of seizures among adults and children following influenza vaccination using health insurance claims data.

Introduction: Post-licensure surveillance of adverse events following vaccination or prescription drug use often relies on electronic healthcare data to efficiently detect and evaluate safety signals. The accuracy of seizure-related diagnosis codes in identifying true incident seizure events in vaccine safety studies is influenced by factors such as clinical setting of diagnosis and age. To date, most studies of post-vaccination seizure have focused on pediatric populations.