Adverse events following adenovirus type 4 and type 7 vaccine, live, oral in the Vaccine Adverse Event Reporting System (VAERS), United States, October 2011-July 2018

BACKGROUND

In March 2011, the U.S. Food and Drug Administration licensed adenovirus type 4 and type 7 vaccine, live, oral (Barr Labs, Inc.) (adenovirus vaccine) for use in military personnel 17 through 50 years of age. The vaccine was first universally administered to U.S. military recruits in October 2011. We investigated adverse event (AE) reports following the adenovirus vaccine submitted to the Vaccine Adverse Event Reporting System (VAERS).

METHODS

We searched the VAERS database for U.S. reports among persons who received adenovirus vaccine during October 2011 through July 2018 including participants in a military observational study. We reviewed all serious reports and accompanying medical records. We compared the proportion of serious reports in a proxy military recruit population and reviewed all reports of suspected allergic reactions following adenovirus vaccination.

RESULTS

During the analytic period, VAERS received 100 reports following adenovirus vaccination; 39 (39%) were classified as serious and of these, 17 (44%) were from the observational study. One death was reported. Males accounted for 72% of reports. Median age of vaccinees was 19 years (range 17-32). The most frequently reported serious AEs were Guillain Barré syndrome (GBS) (n = 12) and anaphylaxis (n = 8); of these, two GBS and all the anaphylaxis reports were reported in the observational study. Reports documented concurrent receipt of multiple other vaccines (95%) and penicillin G (IM Pen G) or other antibiotics (50%).

CONCLUSIONS

The reporting rate for serious AEs was higher than with other vaccines administered in the comparison military recruit population (39% vs 18%); however, we identified no unexpected or concerning pattern of adenovirus vaccine AEs. Co-administration of vaccines and IM Pen G was commonly reported in this military population. These exposures may have contributed to the GBS and anaphylaxis outcomes observed with the adenovirus vaccine. Future adenovirus vaccine safety studies in a population without these co-administrations would be helpful in clarifying the vaccine's safety profile.

Vaccine-Associated Anaphylaxis

PURPOSE OF REVIEW

Anaphylaxis is a rare, serious hypersensitivity reaction following vaccination, which is rapid in onset and characterized by multisystem involvement. Although anaphylaxis may occur after any vaccine, understanding the risk for this outcome, particularly following influenza vaccines, is important because of the large number of persons vaccinated annually. Recent Findings Two recent CDC safety studies confirmed the rarity of post-vaccination anaphylaxis. In a 25-year review of data from the Vaccine Adverse Event Reporting System (VAERS), reports in children were most common following childhood vaccinations and among adults more often followed influenza vaccine. In a Vaccine Safety Datalink (VSD) study, the estimated incidence of anaphylaxis was 1.3 per million vaccine doses administered for all vaccines and 1.6 per million doses for IIV3 (trivalent) influenza vaccine.

SUMMARY

Despite its rarity, its rapid onset (usually within minutes) and potentially lethal nature require that all personnel and facilities providing vaccinations have procedures in place for anaphylaxis management.

Sociodemographic and clinical correlates of human papillomavirus vaccine attitudes and receipt among Wisconsin adolescents

Few studies have assessed adolescent human papillomavirus (HPV) vaccine attitudes and whether they are associated with vaccination uptake. This study characterized HPV vaccine attitudes among male and female adolescents, identified factors associated with attitude changes, and examined associations between attitudes and vaccination receipt. Surveys were administered to adolescents aged 15-16 years who had not completed the HPV vaccine series. A modified version of the Carolina HPV Immunization Attitudes and Beliefs Scale (CHIAS) was employed to assess barriers, harms, ineffectiveness, and uncertainties scores. Surveys were available from 108 participants; 63% were male and 33% had initiated the HPV vaccine series at baseline. CHIAS scores significantly decreased (i.e., became more favorable) between baseline and follow-up for barriers (p = 0.01) and uncertainties (p < 0.01). At least one sociodemographic/clinical factor was associated with changes in each score. Attitude changes were not associated with receipt of HPV vaccine, although adolescents with higher baseline harms scores were significantly less likely to receive an HPV vaccine dose (OR = 0.67). Adolescents' HPV vaccine attitudes slightly improved over a one-year period during which an intervention was implemented. More research is needed to learn how parent and adolescent HPV vaccine attitudes form, and how best to address concerns about vaccine harms.

Vaccination and risk of lone atrial fibrillation in the active component United States military

PURPOSE

To evaluate the hypothesis that receipt of anthrax vaccine adsorbed (AVA) increases the risk of atrial fibrillation in the absence of identifiable underlying risk factors or structural heart disease (lone atrial fibrillation).

METHODS

We conducted a retrospective population-based cohort study among U.S. military personnel who were on active duty during the period from January 1, 1998 through December 31, 2006. International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes were used to identify individuals diagnosed with atrial fibrillation in the Defense Medical Surveillance System, and electronic records were screened to include only individuals without evidence of predisposing medical conditions. We used multivariable Poisson regression to estimate the risk of lone atrial fibrillation after exposure to AVA. We also evaluated possible associations with influenza and smallpox vaccines.

RESULTS

Our study population consisted of 2,957,091individuals followed for 11,329,746 person-years of service. Of these, 2,435 met our case definition for lone atrial fibrillation, contributing approximately 8,383 person-years of service. 1,062,176 (36%) individuals received at least one dose of AVA; the median person time observed post-exposure was 3.6 years. We found no elevated risk of diagnosed lone atrial fibrillation associated with AVA (adjusted risk ratio = 0.99; 95% confidence interval = 0.90, 1.09; p = 0.84). No elevated risk was observed for lone atrial fibrillation associated with influenza or smallpox vaccines given during military service.

CONCLUSIONS

We did not find an increased risk of lone atrial fibrillation after AVA, influenza or smallpox vaccine. These findings may be helpful in planning future vaccine safety research.

Defining the interval for monitoring potential adverse events following immunization (AEFIs) after receipt of live viral vectored vaccines

Live viral vectors that express heterologous antigens of the target pathogen are being investigated in the development of novel vaccines against serious infectious agents like HIV and Ebola. As some live recombinant vectored vaccines may be replication-competent, a key challenge is defining the length of time for monitoring potential adverse events following immunization (AEFI) in clinical trials and epidemiologic studies. This time period must be chosen with care and based on considerations of pre-clinical and clinical trials data, biological plausibility and practical feasibility. The available options include: (1) adapting from the current relevant regulatory guidelines; (2) convening a panel of experts to review the evidence from a systematic literature search to narrow down a list of likely potential or known AEFI and establish the optimal risk window(s); and (3) conducting "near real-time" prospective monitoring for unknown clustering's of AEFI in validated large linked vaccine safety databases using Rapid Cycle Analysis for pre-specified adverse events of special interest (AESI) and Treescan to identify previously unsuspected outcomes. The risk window established by any of these options could be used along with (4) establishing a registry of clinically validated pre-specified AESI to include in case-control studies. Depending on the infrastructure, human resources and databases available in different countries, the appropriate option or combination of options can be determined by regulatory agencies and investigators.

Cluster anxiety-related adverse events following immunization (AEFI): An assessment of reports detected in social media and those identified using an online search engine

BACKGROUND

Adverse events following immunization (AEFI) arising from anxiety have rarely been reported as a cluster(s) in the setting of a mass vaccination program. Reports of clusters of anxiety-related AEFIs are understudied. Social media and the web may be a resource for public health investigators.

METHODS

We searched Google and Facebook separately from Atlanta and Geneva to identify reports of cluster anxiety-related AEFIs. We reviewed a sample of reports summarizing year, country/setting, vaccine involved, patient symptoms, clinical management, and impact to vaccination programs.

RESULTS

We found 39 reports referring to 18 unique cluster events. Some reports were only found based on the geographic location from where the search was performed. The most common vaccine implicated in reports was human papillomavirus (HPV) vaccine (48.7%). The majority of reports (97.4%) involved children and vaccination programs in school settings or as part of national vaccination campaigns. Five vaccination programs were reportedly halted because of these cluster events. In this study, we identified 18 cluster events that were not published in traditional scientific peer-reviewed literature.

CONCLUSIONS

Social media and online search engines are useful resources for identifying reports of cluster anxiety-related AEFIs and the geographic location of the researcher is an important factor to consider when conducting these studies. Solely relying upon traditional peer-reviewed journals may seriously underestimate the occurrence of such cluster events.

Reports of lower respiratory tract infection following dose 1 of RotaTeq and Rotarix vaccines to the Vaccine Adverse Event Reporting System (VAERS), 2008-2016

A 2018 manufacturer post-licensure safety study identified a possible association between Rotarix (RV1) rotavirus vaccine and lower respiratory tract infections (LRTI) in infants within 0-6 days following receipt of RV1 dose 1. We reviewed reports to the Vaccine Adverse Event Reporting System (VAERS) of LRTI occurring 0-6 days and 0-29 days post vaccination following RotaTeq (RV5) or Rotarix (RV1) vaccinations in conjunction with either Prevnar (PCV7) or Prevnar 13 (PCV13), in infants aged 6 to 15 weeks. There was no significant difference in LRTI reports to VAERS in the 0-6 days and 0-29 days following receipt of either RV5 or RV1 given with either pneumococcal vaccine.

Safety of repeated doses of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine in adults and adolescents

In light of waning immunity to pertussis following receipt of tetanus toxoid, reduced diphtheria toxoid and acellular pertussis (Tdap) vaccine, maintaining protection may require repeated Tdap vaccination. We evaluated the safety of repeated doses of tetanus-containing vaccine in 68 915 nonpregnant adolescents and adults in the Vaccine Safety Datalink population who had received an initial dose of Tdap. Compared with 7521 subjects who received a subsequent dose of tetanus toxoid, reduced diphtheria (Td) vaccine, the 61 394 subjects who received a subsequent dose of Tdap did not have significantly elevated risk of medical visits for seizure, cranial nerve disorders, limb swelling, pain in limb, cellulitis, paralytic syndromes, or encephalopathy/encephalitis/meningitis. These results suggest that repeated Tdap vaccination has acceptable safety relative to Tdap vaccination followed by Td vaccination.

Risk of Nontargeted Infectious Disease Hospitalizations Among US Children Following Inactivated and Live Vaccines, 2005-2014

Background

Recent studies have shown that some vaccines have beneficial effects that cannot be explained solely by the prevention of their respective targeted disease(s).

Methods

We used the MarketScan US Commercial Claims Databases for 2005 to 2014 to assess the risk of hospital admission for nontargeted infectious (NTI) diseases in children aged 16 through 24 months according to the last vaccine type (live and/or inactivated). We included children continuously enrolled within a month of birth through 15 months who received at least 3 doses of diphtheria-tetanus-acellular pertussis vaccine by the end of 15 months of age. We used Cox regression to estimate hazard ratios (HRs), stratifying by birthdate to control for age, year, and seasonality and adjusting for sex, chronic diseases, prior hospitalizations, number of outpatient visits, region of residence, urban/rural area of domicile, prematurity, low birth weight, and mother's age.

Results

311663 children were included. In adjusted analyses, risk of hospitalization for NTI from ages 16 through 24 months was reduced for those who received live vaccine alone compared with inactivated alone or concurrent live and inactivated vaccines (HR, 0.50; 95% confidence interval [CI], 0.43, 0.57 and HR, 0.78; 95% CI, 0.67, 0.91, respectively) and for those who received live and inactivated vaccines concurrently compared with inactivated-only (HR, 0.64; 95% CI, 0.58, 0.70).

Conclusions

We found lower risk of NTI disease hospitalizations from age 16 through 24 months among children whose last vaccine received was live compared with inactivated vaccine, as well as concurrent receipt compared with inactivated vaccine.

Vaccination Patterns in Children After Autism Spectrum Disorder Diagnosis and in Their Younger Siblings

IMPORTANCE

In recent years, rates of vaccination have been declining. Whether this phenomenon disproportionately affects children with autism spectrum disorder (ASD) or their younger siblings is unknown.

OBJECTIVES

To investigate if children after receiving an ASD diagnosis obtain their remaining scheduled vaccines according to the Advisory Committee on Immunization Practices (ACIP) recommendations and to compare the vaccination patterns of younger siblings of children with ASD with the vaccination patterns of younger siblings of children without ASD.

DESIGN, SETTING, AND PARTICIPANTS

This investigation was a retrospective matched cohort study. The setting was 6 integrated health care delivery systems across the United States within the Vaccine Safety Datalink. Participants were children born between January 1, 1995, and September 30, 2010, and their younger siblings born between January 1, 1997, and September 30, 2014. The end of follow-up was September 30, 2015.

EXPOSURES

Recommended childhood vaccines between ages 1 month and 12 years.

MAIN OUTCOME AND MEASURE

The proportion of children who received all of their vaccine doses according to ACIP recommendations.

RESULTS

The study included 3729 children with ASD (676 [18.1%] female), 592 907 children without ASD, and their respective younger siblings. Among children without ASD, 250 193 (42.2%) were female. For vaccines recommended between ages 4 and 6 years, children with ASD were significantly less likely to be fully vaccinated compared with children without ASD (adjusted rate ratio, 0.87; 95% CI, 0.85-0.88). Within each age category, vaccination rates were significantly lower among younger siblings of children with ASD compared with younger siblings of children without ASD. The adjusted rate ratios varied from 0.86 for siblings younger than 1 year to 0.96 for those 11 to 12 years old. Parents who had a child with ASD were more likely to refuse at least 1 recommended vaccine for that child's younger sibling and to limit the number of vaccines administered during the younger sibling's first year of life.

CONCLUSIONS AND RELEVANCE

Children with ASD and their younger siblings were undervaccinated compared with the general population. The results of this study suggest that children with ASD and their younger siblings are at increased risk of vaccine-preventable diseases.

Meningococcal conjugate vaccine safety surveillance in the Vaccine Safety Datalink using a tree-temporal scan data mining method

PURPOSE

The objective of our study was to conduct a data mining analysis to identify potential adverse events (AEs) following MENACWY-D using the tree-temporal scan statistic in the Vaccine Safety Datalink population and demonstrate the feasibility of this method in a large distributed safety data setting.

METHODS

Traditional pharmacovigilance techniques used in vaccine safety are generally geared to detecting AEs based on pre-defined sets of conditions or diagnoses. Using a newly developed tree-temporal scan statistic data mining method, we performed a pilot study to evaluate the safety profile of the meningococcal conjugate vaccine Menactra® (MenACWY-D), screening thousands of potential AE diagnoses and diagnosis groupings. The study cohort included enrolled participants in the Vaccine Safety Datalink aged 11 to 18 years who had received MenACWY-D vaccination(s) between 2005 and 2014. The tree-temporal scan statistic was employed to identify statistical associations (signals) of AEs following MENACWY-D at a 0.05 level of significance, adjusted for multiple testing.

RESULTS

We detected signals for 2 groups of outcomes: diseases of the skin and subcutaneous tissue, fever, and urticaria. Both groups are known AEs following MENACWY-D vaccination. We also identified a statistical signal for pleurisy, but further examination suggested it was likely a false signal. No new MENACWY-D safety concerns were raised.

CONCLUSIONS

As a pilot study, we demonstrated that the tree-temporal scan statistic data mining method can be successfully applied to screen broadly for a wide range of vaccine-AE associations within a large health care data network.

Human Papillomavirus Vaccine Coverage and Prevalence of Missed Opportunities for Vaccination in an Integrated Healthcare System

BACKGROUND

Human papillomavirus (HPV) vaccination has been recommended in the United States for female and male adolescents since 2006 and 2011, respectively. Coverage rates are lower than those for other adolescent vaccines. The objective of this study was to evaluate an assessment and feedback intervention designed to increase HPV vaccination coverage and quantify missed opportunities for HPV vaccine initiation at preventive care visits.

METHODS

We examined changes in HPV vaccination coverage and missed opportunities within the adolescent (11-17 years) population at 9 Oregon-based Kaiser Permanente Northwest outpatient clinics after an assessment and feedback intervention. Quarterly coverage rates were calculated for the adolescent populations at the clinics, according to age group (11-12 and 13-17 years), sex, and department (Pediatrics and Family Medicine). Comparison coverage assessments were calculated at 3 nonintervention (control) clinics. Missed opportunities for HPV vaccine initiation, defined as preventive care visits in which a patient eligible for HPV dose 1 remained unvaccinated, were examined according to sex and age group.

RESULTS

An average of 29,021 adolescents were included in coverage assessments. Before the intervention, 1-dose and 3-dose quarterly coverage rates were increasing at intervention as well as at control clinics in both age groups. Postimplementation quarterly trends in 1-dose or 3-dose coverage did not differ significantly between intervention and control clinics for either age group. One-dose coverage rates among adolescents with Pediatrics providers were significantly higher than those with Family Medicine providers (56% vs 41% for 11- to 12-year-old and 82% vs 69% for 13- to 17-year-old girls; 55% vs 40% for 11- to 12-year-old and 78% vs 62% for 13- to 17-year-old boys).

CONCLUSIONS

No significant differences in HPV vaccine coverage were identified at intervention clinics. However, coverage rates were increasing before the start of the intervention and might have been influenced by ongoing health system best practices. HPV vaccine coverage rates varied significantly according to department, which could allow for targeted improvement opportunities.

Anxiety-related adverse events following immunization (AEFI): A systematic review of published clusters of illness

BACKGROUND

Clusters of anxiety-related adverse events following immunization (AEFI) have been observed in several countries and have disrupted country immunization programs. We conducted a systematic literature review to characterize these clusters, to generate prevention and management guidance for countries.

METHODS

We searched seven peer-reviewed databases for English language reports of anxiety-related AEFI clusters (≥2 persons) with pre-specified keywords across 4 categories: symptom term, cluster term, vaccine term, and cluster AEFI phenomenon term/phrase. All relevant reports were included regardless of publication date, case-patient age, or vaccine. Two investigators independently reviewed abstracts and identified articles for full review. Data on epidemiologic/clinical information were extracted from full text review including setting, vaccine implicated, predominant case-patient symptoms, clinical management, community and media response, and outcome/impact on the vaccination program.

RESULTS

Of 1472 abstracts reviewed, we identified eight published clusters, from all six World Health Organization (WHO) regions except the African Region. Seven clusters occurred among children in school settings, and one was among adult military reservists. The size and nature of these clusters ranged from 7 patients in one school to 806 patients in multiple schools. Patients' symptoms included dizziness, headache, and fainting with rapid onset after vaccination. Implicated vaccines included tetanus (2), tetanus-diphtheria (1), hepatitis B (1), oral cholera (1), human papillomavirus (1), and influenza A (H1N1)pdm09 (2). In each report, all affected individuals recovered rapidly; however, vaccination program disruption was noted in some instances, sometimes for up to one year.

CONCLUSIONS

Anxiety-related AEFI clusters can be disruptive to vaccination programs, reducing public trust in immunizations and impacting vaccination coverage; response efforts to restore public confidence can be resource intensive. Health care providers should have training on recognition and clinical management of anxiety-related AEFI; public health authorities should have plans to prevent and effectively manage anxiety-related AEFI clusters. Prompt management of these occurrences can be even more important in an era of social media, in which information is rapidly spread.

Assessing Potential Confounding and Misclassification Bias When Studying the Safety of the Childhood Immunization Schedule

OBJECTIVES

Some parents are concerned the childhood immunization schedule could increase risk for allergic disorders, including asthma. To inform future safety studies of this speculated association, a parent survey was conducted to examine the risk of misclassification of vaccination status in electronic health record data, and to assess the potential for confounding if asthma risk factors varied by vaccination status.

METHODS

A survey was conducted among parents of children 19 to 35 months old at 6 medical organizations within the Vaccine Safety Datalink. Parents of children in 4 vaccination groups were surveyed: 1) no vaccines by 12 months of age and a diagnosis of parental vaccine refusal; 2) consistent vaccine limiting (≤2 vaccines per visit); 3) not consistently vaccine limiting but otherwise undervaccinated with a vaccine refusal diagnosis; and 4) fully vaccinated with no delays and no vaccine refusal. Parents were surveyed about their child's vaccination status and whether asthma risk factors existed.

RESULTS

Among a survey sample of 2043 parents, 1209 responded (59.2%). For receiving no vaccines, the observed agreement between parent report and electronic health record data was 94.0% (κ = 0.79); for receiving all vaccines with no delays, the observed agreement was 87.3% (κ = 0.73). Although most asthma risk factors (allergic rhinitis, eczema, food allergies, family asthma history) reported by parents did not differ significantly between children in the vaccination groups studied, several factors (aeroallergen sensitivity, breastfeeding) differed significantly between groups.

CONCLUSIONS

Measurement and control of disease risk factors should be carefully considered in observational studies of the safety of the immunization schedule.

Current safety issues with quadrivalent meningococcal conjugate vaccines

Invasive meningococcal disease, although rare, can present as sudden, life-threatening disease with high risk of mortality or severe long-term sequelae. The main prevention strategy for invasive meningococcal disease in the United States is the routine vaccination of adolescents and other persons at increased risk of meningococcal disease with quadrivalent meningococcal conjugate vaccines. Two such vaccines are currently licensed and available in the United States, Menactra® (Sanofi Pasteur) and Menveo® (GlaxoSmithKline), and usage in the adolescent population has steadily increased since their introduction. Although early reports raised concerns about a possible association of Menactra with Guillain-Barré syndrome, a comprehensive safety review determined that if such risk existed it was no more than 0.66 cases per 1 million vaccinations. More recently, a study found an elevated risk of Bell's palsy when Menveo was administered concomitantly with other vaccines but no association was found when the vaccine was administered alone. In this commentary, we describe the current state of knowledge with respect to the safety of quadrivalent meningococcal conjugate vaccines, and we identify potential areas for safety research for these vaccines.

Association between parent attitudes and receipt of human papillomavirus vaccine in adolescents

Background

Human papillomavirus (HPV) vaccine coverage rates remain low. This is believed to reflect parental hesitancy, but few studies have examined how changes in parents’ attitudes impact HPV vaccine uptake. This study examined the association between changes in parents’ vaccine attitudes and HPV vaccine receipt in their adolescent children.

Methods

A baseline and 1-year follow-up survey of HPV vaccine attitudes was administered to parents of 11–17 year olds who had not completed the HPV vaccine series. Changes in attitudinal scores (barriers, harms, ineffectiveness, and uncertainties) from the Carolina HPV Immunization Attitudes and Beliefs Scale were assessed. Two outcomes were measured (in parents’ adolescent children) over an 18-month period and analyzed using multivariable regression; receipt of next scheduled HPV vaccine dose and 3-dose series completion.

Results

There were 221 parents who completed the baseline survey (11% response rate) and 164 with available follow-up data; 60% of their adolescent children received a next HPV vaccine dose and 38% completed the vaccine series at follow-up. Decrease in parents’ uncertainties was a significant predictor of vaccine receipt, with each 1-point reduction in uncertainties score associated with 4.9 higher odds of receipt of the next vaccine dose. Higher baseline harms score was the only significant predictor of lower series completion.

Conclusions

Reductions in parents’ uncertainties appeared to result in greater likelihood of their children receiving the HPV vaccine. Only baseline concerns about vaccine harms were associated with lower series completion rate. Education for parents should emphasize the HPV vaccine’s safety profile.

Improving Human Papillomavirus Vaccine Use in an Integrated Health System: Impact of a Provider and Staff Intervention

PURPOSE

Acceptance and coverage of the human papillomavirus (HPV) vaccine in the United States has been suboptimal. We implemented a multifaceted provider and staff intervention over a 1-year period to promote HPV vaccination in a regional health care system.

METHODS

The intervention was conducted in nine clinical departments from February 2015 to March 2016; 34 other departments served as controls. The intervention included in-person provider and staff education, quarterly feedback of vaccine coverage, and system-wide changes to patient reminder and recall notifications. Change in first-dose HPV vaccine coverage and series completion were estimated among 11- to 12-year-olds using generalized estimating equations adjusted for age and sex.

RESULTS

HPV vaccine coverage in the intervention departments increased from 41% to 59%, and the increase was significantly greater than that seen in the control departments (32%-45%, p = .0002). The largest increase occurred in the quarter after completion of the provider and staff education and a patient reminder and recall postcard mailing (p = .004). Series completion also increased significantly system wide among adolescents aged 11-12 years following mailing of HPV vaccine reminder letters to parents of adolescents aged 12 years rather than 16 years.

CONCLUSIONS

HPV vaccine uptake can be improved through a multifaceted approach that includes provider and staff education and patient reminder/recall. System-level change to optimize reminder and recall notices can have substantial impact on HPV vaccine utilization.

Anthrax Vaccine and the Risk of Rheumatoid Arthritis and Systemic Lupus Erythematosus in the U.S. Military: A Case-Control Study

U.S. military personnel assigned to areas deemed to be at high risk for anthrax attack receive Anthrax Vaccine Adsorbed (AVA). Few cases of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) have been reported in persons who received AVA. Using a matched case-control study design, we assessed the relationship of RA and SLE with AVA vaccination using the Defense Medical Surveillance System. We identified potential cases using International Classification of Diseases, 9th Revision, Clinical Modification codes and confirmed cases with medical record review and rheumatologist adjudication. Using conditional logistic regression, we estimated odds ratios (OR) for AVA exposure during time intervals ranging from 90 to 1,095 days before disease onset. Among 77 RA cases, 13 (17%) had ever received AVA. RA cases were no more likely than controls to have received AVA when looking back 1,095 days (OR: 1.03; 95% confidence interval [CI]: 0.48-2.19) but had greater odds of exposure in the prior 90 days (OR: 3.93; 95% CI: 1.08-14.27). Among the 39 SLE cases, 5 (13%) had ever received AVA; no significant difference in receipt of AVA was found when compared with controls (OR: 0.91; 95% CI: 0.26-3.25). AVA was associated with recent onset RA, but did not increase the risk of developing RA in the long term.

Adverse events following quadrivalent meningococcal CRM-conjugate vaccine (Menveo®) reported to the Vaccine Adverse Event Reporting system (VAERS), 2010-2015

BACKGROUND

Limited data are available describing the post-licensure safety of meningococcal vaccines, including Menveo®. We reviewed reports of adverse events (AEs) to the Vaccine Adverse Event Reporting System (VAERS) to assess safety in all age groups.

METHODS

VAERS is a national spontaneous vaccine safety surveillance system co-administered by the Centers for Disease Control and Prevention and the US Food and Drug Administration. We searched the VAERS database for US reports of adverse events in persons who received Menveo from 1 January 2010 through 31 December 2015. We clinically reviewed reports and available medical records for serious AEs, selected pre-specified outcomes, and vaccination during pregnancy. We used empirical Bayesian data mining to identify AEs that were disproportionately reported after receipt of Menveo.

RESULTS

During the study period, VAERS received 2614 US reports after receipt of Menveo. Of these, 67 were classified as serious, including 1 report of death. Adolescents (aged 11-18years) accounted for 74% of reports. Most of the reported AEs were non-serious and described AEs consistent with data from pre-licensure studies. Anaphylaxis and syncope were the two most common events in the serious reports. We did not identify any new safety concerns after review of AEs that exceeded the data mining threshold, although we did observe disproportionate reporting for terms that were not associated with an adverse event (e.g., "incorrect drug dosage form administered", "wrong technique in drug usage process"). Although reports were limited, we did not find any evidence for concern regarding the use of Menveo during pregnancy.

CONCLUSIONS

In our review of VAERS reports, findings of AEs were consistent with the data from pre-licensure studies. Vaccine providers should continue to emphasize and adhere to proper administration of the vaccine.

Assessing misclassification of vaccination status: Implications for studies of the safety of the childhood immunization schedule

BACKGROUND

To address public concern about the safety of the childhood immunization schedule, the Institute of Medicine recommended observational studies comparing adverse health outcomes of fully vaccinated children to children under-vaccinated due to parental choice. Misclassification of vaccination status could bias such studies.

OBJECTIVE

To assess risk of misclassification of vaccination status within the Vaccine Safety Datalink (VSD).

DESIGN/METHODS

A retrospective cohort study was conducted in three phases. In phase 1, electronic health record (EHR) data were used to identify patterns of under-vaccination during the first 24months of life potentially due to parental choice. In phase 2, a random sample of records of under-vaccinated children was manually reviewed. In phase 3, a separate sample of parents were surveyed to assess whether EHR data accurately reflected their child's vaccination status. Phases 1 and 2 were conducted at 6 VSD sites, phase 3 at 1 site.

RESULTS

The study cohort included 361,901 children born 2004 through 2012. By 24months of age, 198,249 (54.8%) were fully vaccinated with no delays, 84,698 (23.4%) experienced delays but were fully vaccinated by 24months of age, 4865 (1.3%) received no vaccines, 3789 (1.0%) delayed starting vaccination until ≥4months of age, 4781 (1.3%) had consistent vaccine-limiting (≤2 vaccines per visit), and the remaining 65,519 (18.1%) were missing vaccine series or doses. When a diagnosis code for vaccine refusal was present in EHR data, encounter notes confirmed vaccine refusal as the reason for under-vaccination for nearly 100% of sampled records. Parent surveys confirmed these findings. Parents of under-vaccinated children were more likely to report visiting an alternative medical provider than parents of fully vaccinated children.

CONCLUSIONS

Specific groups of children, under-vaccinated due to parental choice, can be identified with relatively low likelihood of misclassification of vaccination status using EHR-based vaccine data and diagnosis codes.

Integration of data from a safety net health care system into the Vaccine Safety Datalink

BACKGROUND

In 2013 the Institute of Medicine suggested that the Vaccine Safety DataLink (VSD) should broaden its population by including data of more patients from low income and racially and ethnically diverse backgrounds. In response, Kaiser Permanente Colorado (KPCO) partnered with Denver Health (DH), an integrated safety net health care system, to explore the integration of DH data.

METHODS

We compared three different methods (reference date of September 1, 2013): "Empanelment" (any patient who has had a primary care visit in the past 18months), "Proxy-enrollment" (two health care visits in 3years separated by 90days), and "Enrollment" in a managed care plan. For each of these methods, we compared cohort size, vaccination rates, socio-demographic characteristics, and health care utilization.

RESULTS

The empaneled population at DH provided the best comparison to KPCO. DH's empaneled population was 111,330 (57,173 adults; 54,157 children), while KPCO had 436,290 empaneled patients (336,462 adults; 99,828 children). Vaccination rates in both health care systems for empaneled patients were comparable. Two year-old up-to-date coverage rates were 83.2% (KPCO) and 86.9% (DH); rates for adolescent Tdap and MCV4 were 85.5% (KPCO) and 90.6% (DH). There were significant differences in the two populations in age, gender, race, preferred language, and % Federal Poverty Level (FPL) (DH 70.7%<100% FPL; KPCO 17.4%), as well as in healthcare utilization - for example pediatric emergency department utilization was twice as high at DH.

CONCLUSIONS

Using a cohort of "empaneled" patients, it is possible to integrate data from a safety net health care system that does not have a uniform managed care population into the VSD, and to compare vaccination rates, socio-demographic characteristics, and health care utilization across the two systems. The KPCO-DH collaboration may serve as a model for incorporating data from a safety net healthcare system into the VSD.

Post licensure surveillance of influenza vaccines in the Vaccine Safety Datalink in the 2013-2014 and 2014-2015 seasons

PURPOSE

The changes in each year in influenza vaccine antigenic components as well as vaccine administration patterns may pose new risks of adverse events following immunization (AEs). To evaluate the safety of influenza vaccines annually administered to people ≥ 6 months, we conducted weekly post licensure surveillance for seven pre-specified adverse events following receipt of influenza vaccines during the 2013-2014 and 2014-2015 seasons in the Vaccine Safety Datalink (VSD).

METHODS

We used both a historically-controlled cohort design with the Poisson-based maximized sequential probability ratio test (maxSPRT) and a self-controlled risk interval (SCRI) design with the binomial-based maxSPRT. For each adverse event outcome, we defined the risk interval on the basis of biologic plausibility and prior literature. For the historical cohort design, numbers of expected adverse events were calculated from the prior seven seasons, adjusted for age and site. For the SCRI design, a comparison window was defined either before vaccination or after vaccination, depending on each specific outcome.

RESULTS

An elevated risk of febrile seizures 0-1 days following trivalent inactivated influenza vaccine (IIV3) was identified in children aged 6-23 months during the 2014-2015 season using the SCRI design. We found the relative risk (RR) of febrile seizures following concomitant administration of IIV3 and PCV13 was 5.3 with a 95% CI 1.87-14.75. Without concomitant PCV 13 administration, the estimated risk decreased and was no longer statistically significant (RR: 1.4; CI: 0.54 - 3.61).

CONCLUSION

No increased risks, other than for febrile seizures, were identified in influenza vaccine safety surveillance during 2013-2014 and 2014-2015 seasons in the VSD. Copyright © 2016 John Wiley & Sons, Ltd.

Adverse events following pandemic influenza A (H1N1) 2009 monovalent and seasonal influenza vaccinations during the 2009-2010 season in the active component U.S. military and civilians aged 17-44years reported to the Vaccine Adverse Event Reporting System

BACKGROUND

No comparative review of Vaccine Adverse Event Reporting System (VAERS) submissions following pandemic influenza A (H1N1) 2009 and seasonal influenza vaccinations during the pandemic season among U.S. military personnel has been published.

METHODS

We compared military vs. civilian adverse event reporting rates. Adverse events (AEs) following vaccination were identified from VAERS for adults aged 17-44years after pandemic (monovalent influenza [MIV], and seasonal (trivalent inactivated influenza [IIV3], live attenuated influenza [LAIV3]) vaccines. Military vaccination coverage was provided by the Department of Defense's Defense Medical Surveillance System. Civilian vaccination coverage was estimated using data from the National 2009 H1N1 Flu Survey and the Behavioral Risk Factor Surveillance System survey.

RESULTS

Vaccination coverage was more than four times higher for MIV and more than twenty times higher for LAIV3 in the military than in the civilian population. The reporting rate of serious AE reports following MIV in service personnel (1.19 per 100,000) was about half that reported by the civilian population (2.45 per 100,000). Conversely, the rate of serious AE reports following LAIV3 among service personnel (1.32 per 100,000) was more than twice that of the civilian population. Although fewer military AEs following MIV were reported overall, the rate of Guillain-Barré Syndrome (GBS) (4.01 per million) was four times greater than that in the civilian population. (1.04 per million).

CONCLUSIONS

Despite higher vaccination coverage in service personnel, the rate of serious AEs following MIV was about half that in civilians. The rate of GBS reported following MIV was higher in the military.