Sudden-Onset Sensorineural Hearing Loss after Immunization: A Case-Centered Analysis.

Objective: Case reports of sudden sensorineural hearing loss (SSHL) following vaccines have led to concerns that vaccines may rarely cause hearing loss. Because of this concern, we analyzed for an association between SSHL and vaccinations.

Study Design: We used a case-centered method, equivalent to a case control design using immunization dates from all matched members of the population to calculate exposure to vaccines, rather than sampling.

Five-year Antibody Persistence and Booster Response After 1 or 2 Doses of Meningococcal A, C, W and Y Tetanus Toxoid Conjugate Vaccine in Healthy Children.

Background: We evaluated antibody persistence up to 5 years postvaccination with a quadrivalent meningococcal serogroups A, C, W and Y tetanus toxoid conjugate vaccine (MenACWY-TT), and subsequent booster responses to MenACWY-TT in healthy US children.

Methods: In the initial phase II, open, multicenter study (NCT00471081), 349 infants were randomized (1:1) to receive MenACWY-TT (1 or 2 doses). In the follow-up study (NCT00718666), we evaluated antibody persistence at years 1, 3 and 5 by serum bactericidal assay using human complement (hSBA).

Waning Tdap Effectiveness in Adolescents.

Background And Objective: Because the effectiveness of diphtheria-tetanus-acellular pertussis (DTaP) vaccine wanes substantially after the fifth dose at ages 4 to 6 years, there is a growing cohort of adolescents who rely on tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) for protection against pertussis. Yet despite high Tdap vaccine coverage among adolescents, California experienced large pertussis outbreaks in 2010 and 2014. We investigated Tdap vaccine effectiveness (VE) and waning within Kaiser Permanente Northern California among adolescents exclusively vaccinated with DTaP vaccines.

Maternal Tdap vaccination: Coverage and acute safety outcomes in the vaccine safety datalink, 2007-2013.

Introduction: Since October 2012, the combined tetanus toxoid, reduced diphtheria toxoid, acellular pertussis vaccine (Tdap) has been recommended in the United States during every pregnancy.

Methods: In this observational study from the Vaccine Safety Datalink, we describe receipt of Tdap during pregnancy among insured women with live births across seven health systems. Using a retrospective matched cohort, we evaluated risks for selected medically attended adverse events in pregnant women, occurring within 42 days of vaccination.

Absence of venous thromboembolism risk following quadrivalent human papillomavirus vaccination, Vaccine Safety Datalink, 2008-2011.

Background: To investigate concerns about a potential association between quadrivalent human papillomavirus vaccination (HPV4) and venous thromboembolism (VTE), we conducted a self-controlled case series study in adolescents and young adults 9-26 years of age in the Vaccine Safety Datalink.

Methods: We identified potential VTE cases diagnosed in 2008 through 2011 who had also received at least one HPV4 dose during that period. We confirmed each presumptive diagnosis by medical record review.

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.

Risk of anaphylaxis after vaccination in children and adults.

Background: Anaphylaxis is a potentially life-threatening allergic reaction. The risk of anaphylaxis after vaccination has not been well described in adults or with newer vaccines in children.

Objective: We sought to estimate the incidence of anaphylaxis after vaccines and describe the demographic and clinical characteristics of confirmed cases of anaphylaxis.

An Overview of Quadrivalent Human Papillomavirus Vaccine Safety: 2006 to 2015.

Background: A quadrivalent human papillomavirus (HPV4) type 6/11/16/18 vaccine (GARDASIL/SILGARD®) has been licensed in many countries around the world for the prevention of cervical, vulvar, vaginal, and anal cancers and precancers, as well as external genital warts causally related to HPV types 6/11/16/18. Across 7 phase 3 clinical trials involving more than 29,000 males and females ages 9-45 years, vaccination was generally well tolerated. Because of its expected public health benefit in reducing cervical cancer and other HPV-related diseases, the vaccine has been implemented in the national vaccination programs of several countries, with over 178 million doses distributed worldwide.

Geographic clusters in underimmunization and vaccine refusal.

Background And Objective: Parental refusal and delay of childhood vaccines has increased in recent years and is believed to cluster in some communities. Such clusters could pose public health risks and barriers to achieving immunization quality benchmarks. Our aims were to (1) describe geographic clusters of underimmunization and vaccine refusal, (2) compare clusters of underimmunization with different vaccines, and (3) evaluate whether vaccine refusal clusters may pose barriers to achieving high immunization rates.

Safety of measles-containing vaccines in 1-year-old children.

Background And Objectives: All measles-containing vaccines are associated with several types of adverse events, including seizure, fever, and immune thrombocytopenia purpura (ITP). Because the measles-mumps-rubella-varicella (MMRV) vaccine compared with the separate measles-mumps-rubella (MMR) and varicella (MMR + V) vaccine increases a toddler's risk for febrile seizures, we investigated whether MMRV is riskier than MMR + V and whether either vaccine elevates the risk for additional safety outcomes.

Methods: Study children were aged 12 to 23 months in the Vaccine Safety Datalink from 2000 to 2012.

Licensed pertussis vaccines in the United States. History and current state.

The United States switched from whole cell to acellular pertussis vaccines in the 1990s following global concerns with the safety of the whole cell vaccines. Despite high levels of acellular pertussis vaccine coverage, the United States and other countries are experiencing large pertussis outbreaks. The aim of this article is to describe the historical context which led to acellular pertussis vaccine development, focusing on vaccines currently licensed in the US, and to review evidence that waning protection following licensed acellular pertussis vaccines have been significant factors in the widespread reappearance of pertussis.

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.

The Vaccine Safety Datalink: successes and challenges monitoring vaccine safety.

The Vaccine Safety Datalink (VSD) is a collaborative project between the Centers for Disease Control and Prevention (CDC) and 9 health care organizations. Established in 1990, VSD is a vital resource informing policy makers and the public about the safety of vaccines used in the United States. Large linked databases are used to identify and evaluate adverse events in over 9 million individuals annually.

Receipt of pertussis vaccine during pregnancy across 7 Vaccine Safety Datalink sites.

Objective: In response to widespread pertussis outbreaks and infant deaths, in 2010, the California Department of Health (CDPH) and in 2011 the Advisory Committee on Immunization Practices (ACIP) advised that the tetanus toxoid, reduced diphtheria toxoid and acellular pertussis (Tdap) vaccine be administered during pregnancy. The goals of this study were to describe Tdap coverage among pregnant women following these recommendations.

Methods: In this observational cohort study, we utilized electronic medical record and claims data from seven Vaccine Safety Datalink sites to identify pregnancies and Tdap administrations.

Safety of diphtheria, tetanus, acellular pertussis and inactivated poliovirus (DTaP-IPV) vaccine.

Background: In 2008, a diphtheria, tetanus, acellular pertussis, and inactivated poliovirus combined vaccine (DTaP-IPV) was licensed for use in children 4 through 6 years of age. While pre-licensure studies did not demonstrate significant safety concerns, the number vaccinated in these studies was not sufficient to examine the risk of uncommon but serious adverse events.

Objective: To assess the risk of serious adverse events following DTaP-IPV vaccination.

Live vaccine use and safety in DiGeorge syndrome.

Objective: Live vaccines are generally contraindicated in patients with DiGeorge syndrome (DGS), a congenital disorder characterized by cellular immune deficiency. Vaccine utilization and safety in this population are not well described. This study examined vaccination patterns and adverse events following live immunization (AEFLI) in these individuals.

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.

Risk of intussusception after monovalent rotavirus vaccination.

Background: Although current rotavirus vaccines were not associated with an increased risk of intussusception in large trials before licensure, recent postlicensure data from international settings suggest the possibility of a small increase in risk of intussusception after monovalent rotavirus vaccination. We examined this risk in a population in the United States.

Methods: Participants were infants between the ages of 4 and 34 weeks who were enrolled in six integrated health care organizations in the Vaccine Safety Datalink (VSD) project.

Protective association between rotavirus vaccination and childhood seizures in the year following vaccination in US children.

Background: Rotavirus illness has been linked to childhood seizures. We investigated whether a protective association exists between receipt of rotavirus vaccine and being hospitalized or visiting the emergency department for seizures in the year after vaccination.

Methods: We retrospectively analyzed a cohort of children born after 28 February 2006 (when rotavirus vaccine was licensed in the United States) and enrolled in the Vaccine Safety Datalink (VSD) through November 2009.