BACKGROUND: Uganda has had seven Ebola disease outbreaks, between 2000 and 2022. On Sept 20, 2022, the Ministry of Health declared a Sudan virus disease outbreak in Mubende District, Central Uganda. We describe the epidemiological characteristics and transmission dynamics. METHODS: For this descriptive study, cases were classified as suspected, probable, or confirmed using Ministry of Health case definitions. We investigated all reported cases to obtain data on case-patient demographics, exposures, and signs and symptoms, and identified transmission chains. We conducted a descriptive epidemiological study and also calculated basic reproduction number (R(o)) estimates. FINDINGS: Between Aug 8 and Nov 27, 2022, 164 cases (142 confirmed, 22 probable) were identified from nine (6%) of 146 districts. The median age was 29 years (IQR 20-38), 95 (58%) of 164 patients were male, and 77 (47%) patients died. Symptom onsets ranged from Aug 8 to Nov 27, 2022. The case fatality rate was highest in children younger than 10 years (17 [74%] of 23 patients). Fever (135 [84%] of 160 patients), vomiting (93 [58%] patients), weakness (89 [56%] patients), and diarrhoea (81 [51%] patients) were the most common symptoms; bleeding was uncommon (21 [13%] patients). Before outbreak identification, most case-patients (26 [60%] of 43 patients) sought care at private health facilities. The median incubation was 6 days (IQR 5-8), and median time from onset to death was 10 days (7-23). Most early cases represented health-care-associated transmission (43 [26%] of 164 patients); most later cases represented household transmission (109 [66%]). Overall R(o) was 1·25. INTERPRETATION: Despite delayed detection, the 2022 Sudan virus disease outbreak was rapidly controlled, possibly thanks to a low R(o). Children (aged <10 years) were at the highest risk of death, highlighting the need for targeted interventions to improve their outcomes during Ebola disease outbreaks. Initial care-seeking occurred at facilities outside the government system, showing a need to ensure that private and public facilities receive training to identify possible Ebola disease cases during an outbreak. Health-care-associated transmission in private health facilities drove the early outbreak, suggesting gaps in infection prevention and control. FUNDING: None.

BACKGROUND: On 20 September 2022, Uganda declared its fifth Sudan virus disease (SVD) outbreak, culminating in 142 confirmed and 22 probable cases. The reproductive rate (R) of this outbreak was 1.25. We described persons who were exposed to the virus, became infected, and they led to the infection of an unusually high number of cases during the outbreak. METHODS: In this descriptive cross-sectional study, we defined a super-spreader person (SSP) as any person with real-time polymerase chain reaction (RT-PCR) confirmed SVD linked to the infection of ≥ 13 other persons (10-fold the outbreak R). We reviewed illness narratives for SSPs collected through interviews. Whole-genome sequencing was used to support epidemiologic linkages between cases. RESULTS: Two SSPs (Patient A, a 33-year-old male, and Patient B, a 26-year-old male) were identified, and linked to the infection of one probable and 50 confirmed secondary cases. Both SSPs lived in the same parish and were likely infected by a single ill healthcare worker in early October while receiving healthcare. Both sought treatment at multiple health facilities, but neither was ever isolated at an Ebola Treatment Unit (ETU). In total, 18 secondary cases (17 confirmed, one probable), including three deaths (17%), were linked to Patient A; 33 secondary cases (all confirmed), including 14 (42%) deaths, were linked to Patient B. Secondary cases linked to Patient A included family members, neighbours, and contacts at health facilities, including healthcare workers. Those linked to Patient B included healthcare workers, friends, and family members who interacted with him throughout his illness, prayed over him while he was nearing death, or exhumed his body. Intensive community engagement and awareness-building were initiated based on narratives collected about patients A and B; 49 (96%) of the secondary cases were isolated in an ETU, a median of three days after onset. Only nine tertiary cases were linked to the 51 secondary cases. Sequencing suggested plausible direct transmission from the SSPs to 37 of 39 secondary cases with sequence data. CONCLUSION: Extended time in the community while ill, social interactions, cross-district travel for treatment, and religious practices contributed to SVD super-spreading. Intensive community engagement and awareness may have reduced the number of tertiary infections. Intensive follow-up of contacts of case-patients may help reduce the impact of super-spreading events.

Given its enhanced genetic stability, novel oral poliovirus vaccine type 2 was deployed for type 2 poliovirus outbreak responses under World Health Organization Emergency Use Listing. We evaluated the safety profile of this vaccine. No safety signals were identified using a multipronged approach of passive and active surveillance.

This report introduces a Brighton Collaboration (BC) case definition for autoimmune hepatitis (AIH), which has been classified as a priority adverse event of special interest (AESI), as there were possible cases seen following COVID-19 vaccination. The case definition was developed by a group of subject matter and BC process experts to facilitate safety data comparability across pre- and post-licensure clinical trials, as well as pharmacovigilance activities in multiple settings with diverse resources and healthcare access. The usual BC case definition development process was followed in an expedited manner, and took two months to complete, including finalising the manuscript for publication, instead of the usual 1 year development time. It includes a systematic review of the literature and an expert consensus to define levels of diagnostic certainty for AIH, and provides specific guidelines for data collection and analysis. Histology, serological and biochemical tests and exclusion of alternate diagnosis were considered necessary to define the levels of certainty (definitive, probable and possible). AEFI reports of suspected AIH were independently classified by the WG members to test its useability and these classifications were used to finalise the case definition. The document underwent peer review by external AIH experts and a Reference Group of vaccine safety stakeholders in high-, low- and middle-income countries to ensure case definition useability, applicability, and scientific integrity. The expedited process can be replicated for development of other standardised case definitions for priority AESIs for endemics and epidemics. While applicable to cases reported following immunisation, the case definition is independent of lapsed time following vaccination and, as such, can also be used to determine background incidence for vaccinated and unvaccinated control groups in studies of causal association. While use of this case definition is also appropriate for the study of safety of other products including drugs, it is not meant to guide clinical case management.

Effective surveillance of adverse events following immunization (AEFIs) primarily relies on the collaboration of two partners: national regulatory authorities (NRAs) and national expanded programs on immunization (EPIs). In December 2020, the World Health Organization (WHO) Global Advisory Committee for Vaccine Safety recommended a new case-based indicator of national capacity to monitor immunization safety: at least one serious AEFI reported per 1 million total population per year. To achieve this indicator, WHO-affiliated countries and territories (WHO countries) rely upon data generated from functional AEFI surveillance systems. This report describes 2020-2022 global, regional, and national progress in use of the newly introduced immunization safety monitoring indicator and progress on joint AEFI reporting from national EPIs and NRAs. Among WHO countries, 51 (24%) of 214 implemented the new indicator in 2020, 111 (52%) of 214 implemented it in 2021, and 92 (43%) of 215 in 2022. In 2020, 41 (19%) WHO countries reported AEFI data jointly from EPIs and NRAs; this increased to 55 (26%) in 2021 and 57 (27%) in 2022. These findings, resulting in part from the intensified support for COVID-19 vaccination, demonstrate that national AEFI surveillance systems increasingly support the timely use and sharing of case-based immunization safety data, but work is still needed to strengthen global vaccine safety monitoring.

Despite significant advances in child survival, infectious diseases continue to be among the leading causes of neonatal deaths [1]. Maternal immunization is a well-recognized public health intervention to reduce vaccine-preventable disease-related morbidity and mortality in the pregnant woman, her foetus, and infant from tetanus, pertussis, seasonal influenza, and COVID-19 [2]. The development of new maternal vaccines against respiratory syncytial virus (RSV) and group B streptococcus (GBS) may significantly decrease the morbidity and mortality from these diseases in neonates and infants [2], with the U.S. Food and Drug Administration (FDA) approval for licensure of an RSV vaccine to be administered in pregnancy occurring in August 2023 [3]. | | Ongoing safety assessment of novel vaccines administered during pregnancy requires well-functioning passive and active surveillance systems to collect and assess adverse maternal and neonatal outcomes [4]. In high-income countries (HICs), regulatory authorities, such as the European Medicines Agency (EMA) and the U.S. FDA, require extensive post-authorization safety monitoring activities for products used during pregnancy, including active surveillance for safety-related events through pregnancy registries and observational cohort studies [4], [5], [6]. However, safety surveillance for vaccines used in pregnancy in many low- and middle-income countries (LMICs) currently relies on passive surveillance systems whose output cannot be interpreted appropriately due to lack of information on background rates of adverse events in pregnancy in general and lack of data on the number of pregnant women vaccinated as the relevant specific comparator [4], [5], [6].

BACKGROUND: In 2016, the World Health Organization recommended that a fractional dose of yellow fever (YF) vaccine could be used in persons 2 years of age or older in response to an emergency that resulted in a global shortage of available YF vaccine. However, this recommendation did not extend to the youngest age group licensed for YF vaccine because there were no published data on the use or safety of fractional dose YF vaccination in children aged 9-23 months. We conducted a single-blind randomized controlled trial, comparing the immunogenicity and safety of fractional one-fifth and one-half doses of Bio-Manguinhos 17DD YF vaccine with full dose in children aged 9-23 months old in Uganda. In this paper, we present the interim analysis on safety. METHODS: Children aged 9-23 months presenting for routine well-child services were recruited for inclusion at one of three study sites. We collected data during March 26, 2019-August 31, 2020, on all adverse events following immunization (AEFI) during active surveillance for 28 days post-vaccination using multiple collection tools including a diary card with an objective measurement of fever. An independent team from the Uganda national AEFI Committee investigated and classified serious AEFI (SAE) according to Brighton Collaboration Criteria. RESULTS: Among 1053 enrolled children, 672 (64%) were reported to have a non-serious AEFI (NSAE) and 17 (2%) were reported to have a SAE. The most common AEFI were diarrhoea, fever, and rash, each reported by 355 (34%), 338 (33%), and 188 (18%) participants, respectively. Among 17 participants with SAE, eight were reported to have had seizures and five were hospitalised for seizures or other causes (respiratory symptoms, gastrointestinal illness, malaria). Four SAEs (deaths) occurred >28 days after vaccination. There were no reported cases of pre-specified or vaccine-related SAEs. We observed no significant difference in frequency or severity of adverse events among the study groups. CONCLUSIONS: Using comprehensive active surveillance monitoring, we did not identify any unexpected safety concerns among children aged <2 years receiving YF vaccination, including with the fractional doses. Although we identified a high number of both serious and non-serious AEFI, none were determined to be causally related to YF vaccination. These results provide evidence for the safety of fractional dose YF vaccination among children aged 9-23 months.

Rift Valley fever (RVF) is a zoonotic mosquito-borne viral hemorrhagic fever (VHF) caused by Rift Valley fever virus (RVFV). RVF is endemic throughout most of Africa and the Arabian Peninsula and causes considerable morbidity and mortality among domestic livestock (1,2). Human infection occurs through contact with infected animals or their products or through bites from infected mosquitoes, mainly Aedes and Culex spp. (3). Human infections are typically asymptomatic or mild, usually manifesting as acute influenza-like illnesses (2). Severe disease, including hemorrhagic signs, occurs in approximately 10% of cases, nearly 10%–20% of which are fatal (2). Because of its socioeconomic impact and epidemic potential, RVF is a priority zoonotic disease in Uganda (4). | | On February 4, 2023, the Uganda National Public Health Emergency Operations Center was notified of a suspected viral hemorrhagic fever case in a male abattoir worker and meat roaster aged 42 years from Mbarara City, the second largest city in Uganda. The patient was evaluated at a private health facility on January 30, at which time he reported a 2-day history of influenza-like illness. He received antimalarial medication and was discharged. On February 1, because of worsening signs and symptoms (fever, vomiting, diarrhea, fatigue, anorexia, difficulty breathing, and abdominal, chest, muscle, and joint pain), the patient sought treatment at Mbarara Regional Referral Hospital (MRRH). On February 3, he experienced nosebleed, gingival hemorrhage, hematuria, and bloody stools, and voluntarily left MRRH to seek care at a second, private facility. Suspecting a viral hemorrhagic fever, clinicians isolated him, provided supportive care, and referred him back to MRRH, where he died on February 4. A postmortem blood sample tested at the Uganda Virus Research Institute for any ebolavirus, marburgvirus, Crimean-Congo hemorrhagic fever virus, and RVFV, was positive on February 5 for RVFV by reverse transcription–polymerase chain reaction (RT-PCR) (5), and immunoglobulin M (IgM) and immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA) (3).

The US Centers for Disease Control and Prevention (CDC) supports international partners in introducing vaccines, including those against SARS-CoV-2 virus. CDC contributes to the development of global technical tools, guidance, and policy for COVID-19 vaccination and has established its COVID-19 International Vaccine Implementation and Evaluation (CIVIE) program. CIVIE supports ministries of health and their partner organizations in developing or strengthening their national capacities for the planning, implementation, and evaluation of COVID-19 vaccination programs. CIVIE's 7 priority areas for country-specific technical assistance are vaccine policy development, program planning, vaccine confidence and demand, data management and use, workforce development, vaccine safety, and evaluation. We discuss CDC's work on global COVID-19 vaccine implementation, including priorities, challenges, opportunities, and applicable lessons learned from prior experiences with Ebola, influenza, and meningococcal serogroup A conjugate vaccine introductions.

Nigeria began administering COVID-19 vaccines on 5 March 2021 and is working towards the WHO's African regional goal to fully vaccinate 70% of their eligible population by December 2022. Nigeria's COVID-19 vaccination information system includes a surveillance system for COVID-19 adverse events following immunisation (AEFI), but as of April 2021, AEFI data were being collected and managed by multiple groups and lacked routine analysis and use for action. To fill this gap in COVID-19 vaccine safety monitoring, between April 2021 and June 2022, the US Centers for Disease Control and Prevention, in collaboration with other implementing partners led by the Institute of Human Virology Nigeria, supported the Government of Nigeria to triangulate existing COVID-19 AEFI data. This paper describes the process of implementing published draft guidelines for data triangulation for COVID-19 AEFI data in Nigeria. Here, we focus on the process of implementing data triangulation rather than analysing the results and impacts of triangulation. Work began by mapping the flow of COVID-19 AEFI data, engaging stakeholders and building a data management system to intake and store all shared data. These datasets were used to create an online dashboard with key indicators selected based on existing WHO guidelines and national guidance. The dashboard went through an iterative review before dissemination to stakeholders. This case study highlights a successful example of implementing data triangulation for rapid use of AEFI data for decision-making and emphasises the importance of stakeholder engagement and strong data governance structures to make data triangulation successful.

INTRODUCTION: Despite the emphasis on reporting of Adverse Events Following Immunisation (AEFIs) during didactic training sessions, especially prior to new vaccine introductions, it remains low in Ghana. We explored the factors underlying the under-reporting of AEFI by healthcare workers (HCWs) to provide guidance on appropriate interventions to increase reporting. METHODS: We conducted an exploratory descriptive in-depth study of the factors contributing to low reporting of AEFI among HCWs in four regions in Ghana. Key informant interviews (KII) were held with purposively selected individuals that are relevant to the AEFI reporting process at the district, regional, and national levels. We used KII guides to conduct in-depth interviews and used NVivo 10 qualitative software to analyse the data. Themes on factors influencing AEFI reporting were derived inductively from the data, and illustrative quotes from respondents were used to support the narratives. RESULTS: We conducted 116 KIIs with the health managers, regulators and frontline HCWs and found that lack of information on reportable AEFIs and reporting structures, misunderstanding of reportable AEFIs, heavy workload, cost of reporting AEFIs, fear of blame by supervisors, lack of motivation, and inadequate feedback as factors responsible for underreporting of AEFIs. Respondents suggested that capacity building for frontline HCWs, effective supervision, the provision of motivation and feedback, simplification of reporting procedures, incentives for integrating AEFI reporting into routine monitoring and reporting, standardization of reporting procedures across regions, and developing appropriate interventions to address the fear of personal consequences would help improve AEFI reporting. CONCLUSION: From the perspectives of a broad range of key informants at all levels of the vaccine safety system, we found multiple factors (both structural and behavioural), that may impact HCW reporting of AEFI in Ghana. Improvements in line with the suggestions are necessary for increased AEFI reporting in Ghana.

This is a Brighton Collaboration case definition of thrombosis and thromboembolism to be used in the evaluation of adverse events following immunization, and for epidemiologic studies for the assessment of background incidence or hypothesis testing. The case definition was developed by a group of experts convened by the Coalition for Epidemic Preparedness Innovations (CEPI) in the context of active development of SARS-CoV-2 vaccines. The case definition format of the Brighton Collaboration was followed to develop a consensus definition and defined levels of certainty, after an exhaustive review of the literature and expert consultation. The document underwent peer review by the Brighton Collaboration Network and by selected expert reviewers prior to submission.

BACKGROUND: During February 25-March 4, 2019, Zimbabwe's Ministry of Health and Child Care conducted an emergency campaign using 342,000 doses of typhoid conjugate vaccine (TCV) targeting individuals 6 months-15 years of age in eight high-risk suburbs of Harare and up to 45 years of age in one suburb of Harare. The campaign represented the first use of TCV in Africa outside of clinical trials. METHODS: Three methods were used to capture adverse events during the campaign and for 42 days following the last dose administered: (1) active surveillance in two Harare hospitals, (2) national passive surveillance, and (3) a post-campaign coverage survey. RESULTS: Thirty-nine adverse events were identified during active surveillance, including 19 seizure cases (16 were febrile), 16 hypersensitivity cases, 1 thrombocytopenia case, 1 anaphylaxis case, and two cases with two conditions. Only 21 (54%) of 39 patients were hospitalized and 38 recovered without sequelae. Attack rates per 100,000 TCV doses administered were highest for seizures (6.27) and hypersensitivity (5.02). Only 6 adverse events were reported through passive surveillance by facilities other than the two active surveillance hospitals. A total of 177 (10%) of 1,817 vaccinees surveyed reported experiencing an adverse event during the post-campaign coverage survey, of which 25 (14%) sought care. CONCLUSIONS: In line with previous evaluations of TCV, enhanced adverse event monitoring during an emergency campaign supports the safety of TCV. The majority of reported events were minor or resulted in recovery without long-term sequelae. Attack rates for seizures and hypersensitivity were low compared with previous active surveillance studies conducted in Kenya and Burkina Faso. Strengthening adverse event monitoring in Zimbabwe and establishing background rates of conditions of interest in the general population may improve future safety monitoring during new vaccine introductions.

BACKGROUND: In December 2017, the World Health Organization (WHO) prequalified the first typhoid conjugate vaccine (TCV) (Typbar-TCV). While no safety concerns were identified in pre- and post-licensure studies, WHO's Global Advisory Committee on Vaccine Safety recommended robust safety evaluation with large-scale TCV introductions. During July-August 2018, the Navi Mumbai Municipal Corporation (NMMC) launched the world's first public sector TCV introduction. Per administrative reports, 113,420 children 9 months-14 years old received TCV. METHODS: We evaluated adverse events following immunization (AEFI) using passive and active surveillance via 1) reports from the passive NMMC AEFI surveillance system, 2) telephone interviews with 5% of caregivers of vaccine recipients 48 hours and 7 days post-vaccination, and 3) chart abstraction for adverse events of special interest (AESI) among patients admitted to 5 hospitals using the Brighton Collaboration criteria followed by ascertainment of vaccination status. RESULTS: We identified 222/113,420 (0.2%) AEFI through the NMMC AEFI surveillance system: 211 (0.19%) minor, 2 (0.002%) severe, and 9 (0.008%) serious. At 48 hours post-vaccination, 1,852/5,605 (33%) caregivers reported one or more AEFI, including injection site pain (n=1,452, 26%), swelling (n=419, 7.5%), and fever (n=416, 7.4%). Of the 4,728 interviews completed at 7 days post-vaccination, the most reported AEFI included fever (n=200, 4%), pain (n=52, 1%), and headache (n=42, 1%). Among 525 hospitalized children diagnosed with an AESI, 60 were vaccinated; no AESI were causally associated with TCV. CONCLUSIONS: No unexpected safety signals were identified with TCV introduction. This provides further reassurance for the large-scale use of Typbar-TCV among children 9 months-14 years old.

Seizures are the most common neurological emergency in newborns and can be associated with significant mortality and neuro-developmental disability. Neonatal seizures are a major challenge for clinicians because of inconspicuous clinical presentation, variable electro-clinical correlation, and poor response to antiseizure drugs. It is well recognized that fever and infection can trigger seizures in young children and that this risk is enhanced in children with epilepsy. As immunization may cause a fever, vaccination can be a non-specific trigger for seizures in children [1]. On the other hand, children with epilepsy do not appear to be at increased risk of seizures following immunization [2]. It is unclear whether vaccination in newborns or maternal vaccination, is associated with a higher risk of neonatal seizures. However, as maternal immunization with established vaccines becomes more prevalent across multiple geographies, and new maternal vaccine candidates enter late-stage development, it is becoming increasingly important to create easily adopted standard definitions for adverse events potentially associated with these interventions. The Brighton Collaboration has previously published a case definition for seizures in children [3] but not for seizures in neonates.

Despite didactic training on adverse events following immunization (AEFI) in Ghana, the reporting ratio of AEFI was 1.56 per 100,000 surviving infants in 2015, below the minimum reporting ratio of 10. We aimed to estimate the proportion of health care workers (HCWs) reporting AEFI and to identify barriers to reporting. We conducted a cross-sectional survey of HCWs in four regions in Ghana. A simple random sample of 176 health facilities was selected and up to two HCWs were randomly selected per facility. We used the Rao-Scott Chi-squared test to compare factors associated with reporting of AEFI in the last year. We used an open-ended question to identify reasons for low reporting. One supervisor from each facility, responsible for overall reporting and management of AEFI, was also interviewed. A total of 306 HCWs from 169 facilities were interviewed. Of these, 176 (57.5%) reported they had ever encountered an AEFI. Of the 120 who had encountered an AEFI in the last year, 66 (55.0%) indicated they had reported the AEFI, and 38 (31.7%) completed a reporting form. HCWs (n=120) reported multiple barriers to reporting of AEFI; the most common barriers were fear of personal consequences (44.1%), lack of knowledge or training (25.2%), and not believing an AEFI was serious enough to report (22.2%). Discussion of AEFI during the last supervisory visit was significantly associated with reporting in the past year (OR 7.39; p<.001). Of 172 supervisors interviewed, 65 (37.8%) mentioned their facilties had ever encountered an AEFI; over 90% of facilities had reporting forms. We identified low reporting of AEFI and multiple barriers to reporting among HCWs in the four selected regions of Ghana. Discussing AEFI during supervisory visits with HCWs might improve reporting. Additionally, strategies to address fear of personal consequences as a barrier to reporting of AEFI are needed.

The success of immunization programs in lowering the incidence of vaccine preventable diseases (VPDs) has led to increased public attention on potential health risks associated with vaccines. As a result, a scientifically rigorous response to investigating reported adverse events following immunization (AEFI) and effective risk communications strategies are critical to ensure public confidence in immunization. Globally, an estimated 257 million people have chronic hepatitis B virus (HBV) infection, which causes more than 686,000 premature deaths from liver cancer and cirrhosis. Hepatitis B vaccination is the most effective way to prevent mother-to-child transmission of HBV infection, especially when a timely birth dose is given within 24h of birth. However, an infant's risk of dying is highest in the neonatal period, and thus, administering HepB-BD within 24h of birth overlaps with the most fragile period in an infant's life. A working group formed in July 2016 following the publication of the case reports of the effects on vaccination coverage of media reports of infant deaths after HepB-BD administration in China and Vietnam. The goal of the working group was to create a framework and describe best practices for preparing for and responding to AEFI reported after HepB-BD administration, using existing resources. The framework includes six steps, including three preparation steps and three response steps. This document is written for national and regional immunization program staff. Prior to using the framework for preparation and response to AEFIs reported after HepB-BD administration, staff members should be familiar with how AEFI are detected, reported, and investigated in the country. The document might also be of interest to national regulatory staff members who monitor vaccine safety within the country.

Clinical Trials Registration: ClinicalTrials.gov [NCT02378753] and Pan African Clinical Trials Registry [PACTR201502001037220].

Reporting of adverse events following immunization (AEFI) is a key component for functional vaccine safety monitoring system. The aim of our study is to document trends in the AEFI reporting ratio globally and across the six World Health Organization (WHO) regions. We describe the number of AEFI reports communicated each year through the World Health Organization/United Nations Children's Fund Joint Reporting Form on Immunization from 2000 to 2015. The AEFI reporting ratios (annual AEFI reports per 100,000 surviving infants) were calculated to identify WHO countries (n=191 in 2000 and n=194 by 2015) that met a minimal reporting ratio of 10, a target set by the Global Vaccine Action Plan for vaccine safety monitoring as a proxy measure for a functional AEFI reporting system. The number of countries reporting any AEFI fluctuated over time but with progress from 32 (17%) in 2000 to 124 (64%) in 2015. In 2015, the global average AEFI reporting ratio was 549 AEFI reports per 100,000 surviving infants. The number of countries with AEFI reporting ratiosgreater than10 increased from 8 (4%) in 2000 to 81 (42%) in 2015. In 2015, 60% of countries in the WHO Region of the Americas reported at least 10 AEFI per 100,000 surviving infants, followed by 55% in European Region, 43% in Eastern Mediterranean Region, 33% in Western Pacific Region, 27% in South-East Asia Region and 21% in African Region. Overall, AEFI reporting has increased over the past sixteen years worldwide, but requires strengthening in a majority of low- and middle- income countries. The AEFI reporting ratio is useful for benchmarking and following trends over time; but does not provide information on the quality of the reporting system and does not guarantee capacity to detect and manage a vaccine safety problem at a national level. Additional efforts are required to ensure and improve data quality, AEFI reporting and surveillance of immunization safety in every country.

Vaccination during pregnancy is increasingly being used as an effective approach for protecting both young infants and their mothers from serious infections. Drawing conclusions from published studies in this area can be difficult because of the inability to compare vaccine trial results across different studies and settings due to the heterogeneity in the definitions of terms used to assess the safety of vaccines in pregnancy and the data collected in such studies. The guidelines proposed in this document have been developed to harmonize safety data collection in all phases of clinical trials of vaccines in pregnant women and apply to data from the mother, fetus and infant. Guidelines on the prioritization of the data to be collected is also provided to allow applicability in various geographic, cultural and resource settings, including high, middle and low-income countries.

Facial nerve palsy is classified based on the location of its lesion. Central facial nerve palsy is the consequence of an upper motor neuron (UMN) lesion of the 7th cranial nerve, while peripheral palsy is due to a lesion of a lower motor neuron (LMN). Peripheral facial nerve palsy is the partial (i.e., paresis) or complete (i.e., paralysis) loss of function of some or all the structures innervated by the facial nerve (i.e. cranial nerve VII). Facial nerve palsy is also classified by the time course of its development depending on whether acute (minutes to days), subacute (days to weeks) or chronic (longer than weeks). Acute onset facial palsies are common. The most common cause of acute onset, central facial palsy is stroke. However, of the acute onset, peripheral facial palsies, the most common syndrome is that of idiopathic, acute onset, peripheral facial palsy, better known as Bell's palsy. Henceforth in this document, it will be understood that, when discussing Bell's palsy, we are referring to peripheral facial palsy that is ‘acute-onset’. | Clinical signs of peripheral facial nerve palsy include loss of facial tone with obliteration of the naso-labial fold, inability to raise the eyebrows and wrinkle the forehead, smile, open or draw the corner of the mouth, and completely close the eye on the affected side [1], [2], [3], [4]. They may further include hyperacusis, dryness of eye and decreased salivation. Peripheral facial nerve palsy most commonly presents on one side of the face, leading to facial asymmetry, or “facial droop” [1], [5]. Simultaneous bilateral acute-onset cases have also been described and are now recognised as an uncommon clinical feature [6], [7], [8], [9], [10], [11], [12], [13].

OBJECTIVE: To describe scientific information usage and publication patterns of the Centers for Disease Control and Prevention (CDC) Public Health Library and Information Center patrons. DESIGN: Administratively collected patron usage data and aggregate data on CDC-authored publications from the CDC Library for 3 consecutive years were analyzed. SETTING: The CDC Public Health Library and Information Center, which serves CDC employees nationally and internationally. PARTICIPANTS: Internal patrons and external users of the CDC Library. MAIN OUTCOME MEASURE(S): Three-year trends in full-text article publication and downloads including most common journals used for each purpose, systematic literature searches requested and completed, and subscriptions to a weekly public health current literature awareness service. RESULTS: From 2011 to 2013, CDC scientists published a total of 7718 articles in the peer-reviewed literature. During the same period, article downloads from the CDC Library increased 25% to more than 1.1 million, completed requests for reviews of the scientific literature increased by 34%, and electronic subscriptions to literature compilation services increased by 23%. CONCLUSIONS: CDC's scientific output and information use via the CDC Library are both increasing. Researchers and field staff are making greater use of literature review services and other customized information content delivery. Virtual public health library access is an increasingly important resource for the scientific practice of public health.

BACKGROUND: Monovalent 2009 H1N1 influenza vaccines were licensed and administered in the United States during the H1N1 influenza pandemic between 2009 and 2013. METHODS: Vaccine Adverse Event Reporting System received reports of adverse events following immunization (AEFI) after H1N1 vaccination. Selected reports were referred to the Centers for Disease Control and Prevention's Clinical Immunization Safety Assessment network for additional review. We assessed causality using modified World Health Organization criteria. RESULTS: There were 3,928 reports of AEFI in children younger than age 18 years after 2009 H1N1 vaccination received by January 31, 2010. Of these, 214 (5.4%) were classified as serious nonfatal and 109 were referred to Clinical Immunization Safety Assessment for further evaluation. Ninety-nine (91%) had sufficient initial information to begin investigation and are described here. The mean age was 8 years (range, 6 months-17 years) and 38% were female. Median number of days between vaccination and symptom onset was 2 (range, -11 days to +41 days). Receipt of inactivated, live attenuated, or unknown type of 2009 H1N1 vaccines was reported by 68, 26 and 5 cases, respectively. Serious AEFI were categorized as neurologic events in 47 cases, as hypersensitivity in 15 cases and as respiratory events in 10 cases. At the time of evaluation, recovery was described as complete (61), partial (16), no improvement (1), or unknown (21). Causality assessment yielded the following likelihood of association with 2009 H1N1 vaccination: 8 definitely; 8 probably; 21 possibly; 43 unlikely; 17 unrelated; and 2 unclassifiable. CONCLUSIONS: Most AEFI in children evaluated were not causally related to vaccine and resolved without sequelae. Detailed clinical assessment of individual serious AEFI can provide reassurance of vaccine safety.

Pain is defined as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage” (International Association for the Study of Pain, IASP) [1]. Pain is the most frequent local adverse event following immunization (AEFI) [2], [3], [4], [5]. It results from the stimulation of nociceptive sensory neurons at the time of vaccine administration or inflammatory process in the damaged tissue afterward. | To date, there has not been a commonly accepted, standardized definition and related assessment of immunization site pain as an AEFI [6], [7], [8], [9], [10], [11], [12], [13], [14], [15]. This hinders comparability and uniform reporting of pain across study settings or surveillance systems. Establishing criteria for assessing immunization site pain during and following immunization is important for individuals collecting, analyzing, presenting and/or communicating data on immunization pain as AEFIs.

Despite remarkable success of immunization programmes on a global perspective, vaccines are neither 100% efficacious nor 100% effective. Therefore, vaccination failure, i.e. occurrence of a specific disease in an individual despite previous vaccination, may occur. Vaccination failure may be due to actual vaccine failure or failure to vaccinate appropriately. Universally accepted concepts and definitions of vaccination failure are required to assess and compare the benefit of vaccines used in populations. Here we propose general definitions for types of vaccination failure. In the future, these should be complemented by specific definitions for specific vaccines as needed depending on public health considerations.

OBJECTIVES: We conducted a pilot study of the Integrated Vaccine Surveillance System (IVSS), a novel active surveillance system for monitoring influenza vaccine adverse events that could be used in mass vaccination settings. METHODS: We recruited 605 adult vaccinees from a convenience sample of 12 influenza vaccine clinics conducted by public health departments of two U.S. metropolitan regions. Vaccinees provided daily reports on adverse reactions following immunization (AEFI) using an interactive voice response system (IVR) or the internet for 14 consecutive days following immunization. Followup with nonrespondents was conducted through computer-assisted telephone interviewing (CATI). Data on vaccinee reports were available real-time through a dedicated secure website. RESULTS: 90% (545) of vaccinees made at least one daily report and 49% (299) reported consecutively for the full 14-day period. 58% (315) used internet, 20% (110) IVR, 6% (31) CATI, and 16% (89) used a combination for daily reports. Of the 545 reporters, 339 (62%) reported one or more AEFI, for a total of 594 AEFIs reported. The majority (505 or 85%) of these AEFIs were mild symptoms. CONCLUSIONS: It is feasible to develop a system to obtain real-time data on vaccine adverse events. Vaccinees are willing to provide daily reports for a considerable time post vaccination. Offering multiple modes of reporting encourages high response rates. Study findings on AEFIs showed that the IVSS was able to exhibit the emerging safety profile of the 2008 seasonal influenza vaccine.

Thank you for your editorial in the December 6, 2010 issue titled “Developing the Next Generation of Vaccinologists” [1]. While we support your call for expanded formal vaccinology training, we also wish to point out that the Centers for Disease Control and Prevention (CDC)’s Immunization Safety Office (ISO) currently has two programs focused on mentoring and training in vaccine safety. | The oldest training opportunity is an ISO position within CDC's Epidemic Intelligence Service (EIS) program (http://www.cdc.gov/eis/index.html). EIS is a 2-year post-graduate training program of service and on-the-job learning for health professionals that provides “hands-on” practical training in epidemiology and public health [2], [3]. Over the past 15 years, 11 EIS Officers have received training in immunization safety through assignments with ISO.

Diarrhea, also spelled diarrhoea, is a common medical condition that is characterized by increased frequency of bowel movements and increased liquidity of stool [1], [2]. Although acute diarrhea is typically self-limiting, it can be severe and can lead to profound dehydration, which can lead to abnormally low blood volume, low blood pressure, and damage to the kidneys, heart, liver, brain and other organs. Acute diarrhea remains a major cause of infant mortality around the world. Over 2 million deaths are attributed to acute diarrhea each year world-wide, most of them in the developing world. [3], [4], [5]. Children and the elderly are particularly prone to dehydration secondary to diarrhea. | Diarrhea has been defined over time by various scientific groups and health organizations in different ways, such as: “the passage of loose unformed stools” [6] or “three looser-than normal stools in a 24-h period” [7], [8] with emphasis on the consistency of stools rather than the number [9]. In epidemiological studies, diarrhea is usually defined as the passage of three or more loose or watery stools in a 24-h period, a loose stool being one that takes the shape of a stool container [8], [9], [10], [11], [12], [13], [14], [15], [16].

Among the various events reported as adverse outcomes following immunizations, neurologic adverse events following immunization (AEFI) are among the most severe and the most difficult to assess. The multifaceted presentation of neurologic illness, the relative lack of familiarity of many clinicians with the approach to and diagnosis of neurologic disease, and the relative scarcity of trained neurologists in many parts of the world make neurologic AEFI some of the most challenging issues in clinical vaccinology. Further, the severity of central and peripheral nervous system events in individual patients often heightens the concern when such illnesses are associated with antecedent immunizations. The lack of a common definition of GBS and FS hinders comparability and uniform reporting of these adverse events. | Sections 2 Clinical case definitions: Guillain–Barré syndrome (GBS), 3 Guidelines for data collection, analysis, and presentation of GBS and FS as adverse events following immunization of this paper provide the case definitions and guidelines for data collection, analysis, and presentation that the Brighton Collaboration GBS Working Group (hereafter referred to as the Working Group) has developed for the standardized collection and assessment of information about GBS and FS. Widespread use of these definitions with their guidelines will improve data comparability and allow for a better understanding of these neurological events that are applicable in study settings with different availability of resources, in health care settings that differ by availability of and access to health care, and in different geographic regions.