BACKGROUND: Following the authorization and recommendations for use of the U.S. COVID-19 vaccines, the Centers for Disease Control and Prevention (CDC)'s Immunization Safety Office (ISO) responded to inquiries and questions from public health officials, healthcare providers, and the general public on COVID-19 vaccine safety. METHODS: We describe COVID-19 vaccine safety inquiries, by topic, received and addressed by ISO from December 1, 2020-August 31, 2022. RESULTS: Of the 1978 COVID-19 vaccine-related inquiries received, 1655 specifically involved vaccine safety topics. The most frequently asked-about topics included deaths following vaccination, myocarditis, pregnancy, and reproductive health outcomes, understanding or interpreting data from the Vaccine Adverse Event Reporting System (VAERS), and thrombosis with thrombocytopenia syndrome. CONCLUSIONS: Inquiries about vaccine safety generally reflect issues that receive media attention. ISO will continue to monitor vaccine safety inquiries and provide accurate and timely information to healthcare providers, public health officials, and the general public.

BACKGROUND: Kratom, a psychoactive substance, use is an evolving research area that needs more studies to augment the limited literature. Our study examines the association between kratom use categories and mental health and substance use disorders in the U.S. METHODS: We used the 2020 National Survey on Drug Use and Health data (N = 32,893), a cross-sectional survey data, on the U.S. population aged 12 years or older. We used STATA/SE version 16 to perform a multinomial logistic regression analysis to assess our study aims. RESULTS: Bisexuals, compared to heterosexuals, had higher risks of kratom use within the past 30 days (relative risk ratio [RRR]= 2.47, 95% CI= 1.07, 5.71). Major depressive episode was positively associated with kratom use more than 30 days ago (RRR= 2.04, 95% CI= 1.24, 3.34). This association was also observed for mild (RRR= 2.04, 95% CI= 1.38, 3.02), moderate (RRR= 2.25, 95% CI= 1.13, 4.51), or severe alcohol use disorder (RRR= 1.88, 95% CI= 1.05, 3.36); and mild (RRR= 1.98, 95% CI= 1.27, 3.11), moderate (RRR= 2.38, 95% CI= 1.27, 4.45), or severe marijuana use disorder (RRR= 2.13, 95% CI= 1.02, 4.47). Illicit drug other than marijuana use disorder was associated positively with kratom use more than 30 days ago (RRR= 2.81, 95% CI= 1.85, 4.26) and kratom use within the past 30 days (RRR= 5.48, 95% CI= 1.50, 20.02). CONCLUSIONS: Our findings suggested that identifying as bisexual, experiencing depression, alcohol use disorder, or illicit drug use disorder increased the risks of kratom use. There is a need to consider mental health and substance use disorders and sexual identity in kratom use interventions and policies geared toward reducing or preventing kratom use.

BACKGROUND: Annual influenza vaccination is recommended for persons 6 months or older and vaccination in infants less than 6 months old is a vaccine administration error. There are limited safety studies in this population, particularly among infants less than 6 weeks old. METHODS: We searched the U.S. Vaccine Adverse Event Reporting System (VAERS) database for reports of adverse events (AEs) following influenza vaccination in infants less than 6 months old for the 2010-2018 influenza seasons. We conducted a descriptive and qualitative analysis of reports to describe AEs and identify possible risk factors. RESULTS: In total, 114 reports were identified; only 21 reported a specific AE. Pyrexia, irritability, crying and diarrhea were the most common symptoms. There were 12 reports involving newborns; the most common circumstance cited was confusion with the birth dose of hepatitis B vaccine. The following risk factors were identified: (1) individuals getting vaccinated together resulting in patient mix-ups; (2) healthcare provider not verifying the patient's information; (3) individual provider confusion due to similarities in vaccines' packaging and names of vaccines that sound alike. CONCLUSIONS: Reports identified of influenza vaccination in infants less than 6 months old indicate that vaccination errors in this age group are occurring and healthcare providers who vaccinate infants should be aware of how to prevent such events. Our study adds to the existing literature by providing valuable information regarding the general absence of serious adverse events in the case of vaccination errors associated with inadvertent influenza vaccine within this population.

BACKGROUND: Human papillomavirus (HPV) vaccines prevent infection with oncogenic virus types. We analyzed reports to the U.S. Vaccine Adverse Event Reporting System (VAERS) of adverse events (AE) following bivalent HPV vaccine (2vHPV). METHODS: We conducted descriptive analysis of 2vHPV reports, reviewed individual reports, calculated crude AE reporting rates, and conducted empirical Bayesian data mining. RESULTS: Of 241 2vHPV reports, 158 were in females, 64 in males (2vHPV is approved for females only), and 19 with unknown sex; 95.8% were classified as non-serious. Dizziness, headache, nausea and injection site reactions were the most common symptoms. Crude AE reporting rates were 33.3 reports per 100,000 doses distributed overall, and 1.4 per 100,000 for serious reports. Empirical Bayesian data mining identified disproportional reporting for three types of medical errors; assessment indicated findings were likely driven by inadvertent 2vHPV use in males. CONCLUSIONS: We did not identify any new or unexpected safety concerns in our review of 2vHPV reports to VAERS.

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.

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.

INTRODUCTION: The Vaccine Adverse Event Reporting System (VAERS) is the spontaneous (passive) reporting system CDC and FDA use to monitor vaccine safety. We used cognitive testing to evaluate proposed revisions to the current VAERS form. METHODS: We conducted in-person cognitive interviews with 22 volunteers to evaluate proposed revisions in a prototype VAERS 2.0 form (new VAERS form). We analyzed data using thematic analysis. RESULTS: Repeating themes included preferences for: brevity, simplicity and clarity; features to minimize time requirements and facilitate ease of completion; logical ordering of questions by topic and importance; and visual cues like color-coded highlighting. Interviews identified instances of discordance between the intended meaning questions (from the perspective of CDC and FDA) and interpretation by volunteers. CONCLUSIONS: Cognitive testing yielded useful information to guide further revisions of the VAERS form. Cognitive testing can be an effective tool for public health programs interested in developing surveys and reporting forms.

Introduction: There have been isolated case reports of medication product mix-ups involving insulin unintentionally given to patients when the intent was to administer vaccines. Information on how and why these types of errors occur is limited. Objective: To describe incidents of unintentional administration of insulin instead of influenza vaccine and identify possible causes for errors. Methods: We describe a 2014 investigation of an apparent mix-up where a cluster of five adult patients unintentionally received insulin instead of influenza vaccine. We also searched Centers for Disease Control and Prevention (CDC) and US Food and Drug Administration (FDA) vaccine and drug safety monitoring databases from January 2005 to April 2015 in order to identify other incidents. We classified cases as either ‘highly suggestive’ or ‘suggestive’ of insulin and influenza vaccine mix-ups. Results: Investigation of the primary cluster incident revealed deviations from recommended practices for storage, handling, preparation, and administration of drugs and vaccines; the five cases were classified as highly suggestive of insulin and influenza vaccine mix-ups. Our search of CDC and FDA vaccine and drug safety monitoring databases identified an additional two highly suggestive and 15 suggestive cases, for a total of 22 cases (7 highly suggestive and 15 suggestive) during the 10-year study period. Conclusion: Insulin and vaccine mix-ups have the potential to cause serious harm to patients, and are preventable with proper training and application of standards. Our investigation indicated that improper storage—including inadequate segregation of insulin and influenza vaccine products in clearly labeled containers or bins—lack of standardized procedures for confirming the contents of vials, and decreased vigilance in preparation and administration likely contributed to the primary cluster incident.