Vaccine-Preventable Disease Outbreaks among Healthcare Workers: A Scoping Review.

BACKGROUND: Outbreaks of vaccine preventable diseases (VPDs) in health care workers (HCWs) can result in morbidity and mortality and cause significant disruptions to health care services, patients and visitors as well as an added burden on the health system. This scoping review is aimed to describe the epidemiology of VPD outbreaks in HCW, caused by diseases which are prevented by the ten vaccines recommended by World Health Organization (WHO) for HCWs. METHODS: In April 2022 CINAHL, MEDLINE, Global Health and EMBASE were searched for all articles reporting on VPD outbreaks in HCWs since the year 2000. Articles were included regardless of language and study type. Clinical and epidemiological characteristics of VPD outbreaks were described. RESULTS: Our search found 9363 articles, of which 216 met inclusion criteria. Studies describing six of the ten VPDs were found: influenza, measles, varicella, tuberculosis, pertussis and rubella. Most articles (93%) were from high- and upper middle-income countries. While most outbreaks occurred in hospitals, several influenza outbreaks were reported in long term care facilities. Based on available data, vaccination rates amongst HCWs were rarely reported. CONCLUSION: We describe several VPD outbreaks in HCWs from 2000 to April 2022. The review emphasises the need to understand the factors influencing outbreaks in HCWs and highlight importance of vaccination amongst HCWs.

Influence of the COVID-19 pandemic on caregiver beliefs and experiences of routine childhood immunisation in Indonesia.

The COVID-19 pandemic contributed to significant health services declines in South-East Asia including Indonesia, which experienced a decline in routine immunisation of children. This study investigated the influence of the pandemic on the beliefs and experiences of caregivers of children related to routine immunisation. This study involved a cross-sectional survey among 1399 caregivers of children aged 0-24 months in Central Java and West Nusa Tenggara provinces from March-April 2022. Data on beliefs and experiences of childhood immunizations were captured using core items from the WHO/UNICEF Behavioural and Social Drivers of Immunization (BeSD) survey. Bivariate and multivariate logistic regression analyses identified factors associated with uptake of routine immunisations. While nearly all caregivers (95.7%) reported wanting their child to receive all recommended routine immunisations, only 40.3% of children aged 2-24 months were up-to-date with all vaccines for age. Factors associated with up-to-date included higher parental education (aOR: 1.76, 95% CI 1.02-3.05), higher household income (aOR: 1.54, 95% CI 1.09-2.18), and caregivers who found it moderately or very easy to get immunisations (aOR: 2.26/2.22, 95% CI 1.06-4.83/1.06-4.69). Recovery efforts should prioritise responding to the factors associated with immunisation status (e.g., perceived ease of access) and on families experiencing disadvantage (e.g., caregivers with lower education and household income) to ensure protections against future outbreaks that are responsive to the context-specific needs and priorities of districts and communities.

Machine learning prediction models for clinical management of blood-borne viral infections: a systematic review of current applications and future impact.

BACKGROUND: Machine learning (ML) prediction models to support clinical management of blood-borne viral infections are becoming increasingly abundant in medical literature, with a number of competing models being developed for the same outcome or target population. However, evidence on the quality of these ML prediction models are limited. OBJECTIVE: This study aimed to evaluate the development and quality of reporting of ML prediction models that could facilitate timely clinical management of blood-borne viral infections. METHODS: We conducted narrative evidence synthesis following the synthesis without meta-analysis guidelines. We searched PubMed and Cochrane Central Register of Controlled Trials for all studies applying ML models for predicting clinical outcomes associated with hepatitis B virus (HBV), human immunodeficiency virus (HIV), or hepatitis C virus (HCV). RESULTS: We found 33 unique ML prediction models aiming to support clinical decision making. Overall, 12 (36.4%) focused on HBV, 10 (30.3%) on HCV, 10 on HIV (30.3%) and two (6.1%) on co-infection. Among these, six (18.2%) addressed the diagnosis of infection, 16 (48.5%) the prognosis of infection, eight (24.2%) the prediction of treatment response, two (6.1%) progression through a cascade of care, and one (3.03%) focused on the choice of antiretroviral therapy (ART). Nineteen prediction models (57.6%) were developed using data from high-income countries. Evaluation of prediction models was limited to measures of performance. Detailed information on software code accessibility was often missing. Independent validation on new datasets and/or in other institutions was rarely done. CONCLUSION: Promising approaches for ML prediction models in blood-borne viral infections were identified, but the lack of robust validation, interpretability/explainability, and poor quality of reporting hampered their clinical relevance. Our findings highlight important considerations that can inform standard reporting guidelines for ML prediction models in the future (e.g., TRIPOD-AI), and provides critical data to inform robust evaluation of the models.

Measuring National Immunization System Performance: A Systematic Assessment of Available Resources.

BACKGROUND: Vaccination coverage is widely used to assess immunization performance but, on its own, provides insufficient information to drive improvements. Assessing the performance of underlying components of immunization systems is less clear, with several monitoring and evaluation (M&E) resources available for use in different operational settings and for different purposes. We studied these resources to understand how immunization system performance is measured. METHODS: We reviewed peer-reviewed and gray literature published since 2000 to identify M&E resources that include national-level indicators measuring the performance of immunization systems or their components (governance, financing, regulation, information systems, vaccine logistics, workforce, service delivery, and demand generation). We summarize indicators by the system components or outcomes measured and describe findings narratively. RESULTS: We identified 20 resources to monitor immunization program objectives and guide national strategic decision-making, encompassing 631 distinct indicators. Indicators for immunization program outcomes comprised the majority (124/631 [19.7%]), largely vaccination coverage (110/124 [88.7%]). Almost all resources (19/20 [95%]) included indicators for vaccine logistics (83/631 [13.2%]), and those for regulation (19/631 [3.0%]) and demand generation (28/631 [4.4%]) were least common. There was heterogeneity in how information systems (92/563 [14.6%]) and workforce (47/631 [7.4%]) were assessed across resources. Indicators for vaccination coverage in adults, data use in decision-making, equity and diversity, effectiveness of safety surveillance, and availability of a public health workforce were notably lacking. CONCLUSIONS: Between the resources identified in this review, we identified considerable variability and gaps in indicators assessing the performance of some immunization system components. Given the multitude of indicators, policymakers may be better served by tailoring evaluation resources to their specific context to gain useful insight into health system performance and improve data use in decision-making for immunization programs.

A pilot study to develop assessment tools for Group A Streptococcus surveillance studies.

Introduction: Group A Streptococcus (GAS) causes pharyngitis (sore throat) and impetigo (skin sores) GAS pharyngitis triggers rheumatic fever (RF) with epidemiological evidence supporting that GAS impetigo may also trigger RF in Australian Aboriginal children. Understanding the concurrent burden of these superficial GAS infections is critical to RF prevention. This pilot study aimed to trial tools for concurrent surveillance of sore throats and skins sore for contemporary studies of RF pathogenesis including development of a sore throat checklist for Aboriginal families and pharynx photography. Methods: Yarning circle conversations and semi-structured interviews were performed with Aboriginal caregivers and used to develop the language and composition of a sore throat checklist. The sore throat story checklist was combined with established methods of GAS pharyngitis and impetigo surveillance (examination, bacteriological culture, rapid antigen detection and serological tests) and new technologies (photography) and used for a pilot cross-sectional surveillance study of Aboriginal children attending their health clinic for a routine appointment. Feasibility, acceptability, and study costs were compiled. Results: Ten Aboriginal caregivers participated in the sore-throat yarning circles; a checklist was derived from predominant symptoms and their common descriptors. Over two days, 21 Aboriginal children were approached for the pilot surveillance study, of whom 17 were recruited; median age was 9 years [IQR 5.5-13.5], 65% were female. One child declined throat swabbing and three declined finger pricks; all other surveillance elements were completed by each child indicating high acceptability of surveillance assessments. Mean time for screening assessment was 19 minutes per child. Transport of clinical specimens enabled gold standard microbiological and serological testing for GAS. Retrospective examination of sore throat photography concorded with assessments performed on the day. Conclusion: Yarning circle conversations were effective in deriving culturally appropriate sore throat questionnaires for GAS pharyngitis surveillance. New and established tools were feasible, practical and acceptable to participants and enable surveillance to determine the burden of superficial GAS infections in communities at high risk of RF. Surveillance of GAS pharyngitis and impetgio in remote Australia informs primary RF prevention with potential global translation.

The development of a machine learning algorithm for early detection of viral hepatitis B infection in Nigerian patients.

Access to Hepatitis B Virus (HBV) testing for people in low-resource settings has long been challenging due to the gold standard, enzyme immunoassay, being prohibitively expensive, and requiring specialised skills and facilities that are not readily available, particularly in remote and isolated laboratories. Routine pathology data in tandem with cutting-edge machine learning shows promising diagnostic potential. In this study, recursive partitioning ("trees") and Support Vector Machines (SVMs) were applied to interrogate patient dataset (n = 916) that comprised results for Hepatitis B Surface Antigen (HBsAg) and routine clinical chemistry and haematology blood tests. These algorithms were used to develop a predictive diagnostic model of HBV infection. Our SVM-based diagnostic model of infection (accuracy = 85.4%, sensitivity = 91%, specificity = 72.6%, precision = 88.2%, F1-score = 0.89, Area Under the Receiver Operating Curve, AUC = 0.90) proved to be highly accurate for discriminating HBsAg positive from negative patients, and thus rivals with immunoassay. Therefore, we propose a predictive model based on routine blood tests as a novel diagnostic for early detection of HBV infection. Early prediction of HBV infection via routine pathology markers and pattern recognition algorithms will offer decision-support to clinicians and enhance early diagnosis, which is critical for optimal clinical management and improved patient outcomes.

Serology study of healthcare workers following a hospital-based outbreak of COVID-19 in North West Tasmania, Australia, 2020.

Introduction: Healthcare facilities are high-risk settings for coronavirus disease 2019 (COVID-19) transmission. Early in the COVID-19 pandemic, the first large healthcare-associated outbreak within Australia occurred in Tasmania. Several operational research studies were conducted amongst workers from the implicated hospital campus, to learn more about COVID-19 transmission. Methods: Healthcare workers (HCWs) from the implicated hospital campus were invited to complete an online survey and participate in a serology study. Blood samples for serological testing were collected at approximately 12 weeks (round one) and eight months (round two) after the outbreak. A descriptive analysis was conducted of participant characteristics, serology results, and longevity of antibodies. Results: There were 261 HCWs in round one, of whom 44 (17%) were polymerase chain reaction (PCR) confirmed outbreak cases; 129 of the 261 (49%) participated in round two, of whom 34 (27%) were outbreak cases. The prevalence of positive antibodies at round one was 15% (n = 38) and at round two was 12% (n = 15). There were 15 participants (12%) who were seropositive in both rounds, with a further 9% (n = 12) of round two participants having equivocal results after previously being seropositive. Six HCWs not identified as cases during the outbreak were seropositive in round one, with three still seropositive in round two. Of those who participated in both rounds, 68% (n = 88) were seronegative at both time points. Discussion: Our findings demonstrate that serological testing after this large healthcare-associated COVID-19 outbreak complemented the findings of earlier diagnostic testing, with evidence of additional infections to those diagnosed when use of PCR testing had been restricted. The results also provide evidence of persisting SARS-CoV-2 antibody response eight months after an outbreak in an unvaccinated population. The high proportion of HCWs who remained seronegative is consistent with low community transmission in Tasmania after this outbreak.

Psychological and financial impacts of COVID-19-related travel measures: An international cross-sectional study.

BACKGROUND: The impact of COVID-19 international travel restrictions has to date, not been fully explored, and with the ongoing threat that new variants could potentially restrict movement further, it is important to consider the impacts that travel restrictions have on community members. This study aimed to evaluate the psychological and financial impact of COVID-19 travel restrictions on those separated from their partners or immediate families, as well as temporary visa holders who were unable to migrate. METHODS: Between 4 November 2021 to 1 December 2021, we executed a cross-sectional online survey targeting three specific groups; (1) those stranded from their partners; (2) those stranded from immediate families; and (3) temporary visa holders unable to migrate or cross international borders. We collected data on respondents' demographic profile; the nature of COVID-19-related travel impacts; depression, anxiety, and stress levels (using the validated DASS-21); and finally, data on respondents financial, employment and accommodation situation. RESULTS: 1363 respondents located globally completed the survey. 71.2% reported financial stress, 76.8% ([Formula: see text], SD = 5.94) reported moderate-to-extremely severe depression, 51.6% ([Formula: see text], SD = 5.49) moderate-to-extremely severe anxiety, and 62.6% ([Formula: see text], SD = 5.55) moderate-to-extremely severe stress levels. Statistically significant factors associated with moderate-to-extremely severe depression, anxiety, and stress included being female, chronic illness, and experiencing financial stress. Employment during COVID-19 -specifically essential services workers or unemployed-was associated with higher levels of anxiety and stress, with only essential workers being a predictor of higher stress severity. Factors that provided psychological protection included being older and having children. CONCLUSION: This study is one of the first to explore the impact COVID-19-related international travel restrictions have had on the financial status and psychological health of affected individuals. It highlights the significant human cost associated with the restrictions and identifies psychologically vulnerable populations. These results will help the design of targeted health and social policy responses.

Vaccine breakthrough infections in a highly-vaccinated Australian population during a SARS-CoV-2 Delta outbreak.

Abstract: Over 80% of residents in the Australian Capital Territory were fully vaccinated within 10 weeks of a SARS-CoV-2 Delta variant outbreak. Of the outbreak's 1,545 cases, 10% were breakthrough infections. The incidence of infections among fully- and partially-vaccinated people was 98.5% and 90% lower, respectively, than for unvaccinated people.

Examining the psychological and financial impact of travel restrictions on citizens and permanent residents stranded abroad during the COVID-19 pandemic: international cross-sectional study.

OBJECTIVES: This study aimed to evaluate the psychological and financial distress reported by citizens and permanent residents stranded abroad due to international travel restrictions introduced in response to the COVID-19 pandemic. DESIGN: An international cross-sectional study. SETTING: A primary analysis of data collected between July and September 2021 through an online survey targeting individuals stranded abroad and unable to return to their country of residence due to international travel restrictions. RESPONDENTS: A total of 1054 individuals aged 18-84 years. DATA ANALYSIS: Multivariable logistic regression models were used to explore the relationship between higher levels of depression, anxiety and stress and participant variables. OUTCOME MEASURES: The survey answered questions regarding COVID-19 travel restriction-related impacts: personal stress, anxiety and depression (using the validated 21-item Depression, Anxiety and Stress Scale (DASS-21) tool), as well as impacts on housing and financial security and demographic data. RESULTS: A total of 75.4% of respondents reported wanting to return to the Oceania region (75.4%), with 45% stranded in Europe. 64.2% reported financial distress while stranded abroad. 64.4% (x̄=9.43, SD=5.81) reported moderate-to-extremely severe (based on the DASS-21 classification) levels of depression, 41.7% for anxiety (x̄=5.46, SD=4.74), and 58.1% for stress (x̄=10.64, SD=5.26). Multivariable analysis indicated that financial stress, an employment change, being <30 years, having a high perceived risk of contracting COVID-19 abroad and being stranded for >2 months were significantly related to scores of moderate-to-extremely severe depression, anxiety and stress. CONCLUSION: The study is among the first to explore the psychological and financial distress-related impacts associated with being stranded abroad due to COVID-19 travel restrictions. It highlights a range of unintended consequences that arise from pandemic-related travel restrictions, identifies the health and social needs of a particularly vulnerable population, and provides clues as to the types of support that may be adopted to best support them.

Severity of Rotavirus-Vaccine-Associated Intussusception: Prospective Hospital-Based Surveillance, Australia, 2007-2018.

BACKGROUND: Multiple studies have shown an association between intussusception (IS) and receipt of monovalent or pentavalent rotavirus vaccine (RV) in the previous 21 days. Disease severity is an important consideration for risk-benefit evaluations of RV, but no studies have compared the severity of IS within 21 days of vaccination (vaccine-associated, VA) and later (not temporally-associated, VNA). METHODS: We used active hospital-based surveillance in the Australian Paediatric Active Enhanced Disease Surveillance (PAEDS) network (July 2007 to February 2018) to identify infants ≤9 months of age meeting Brighton level 1 criteria for IS. We used five severity levels: (1) no surgery and length of stay (LOS) ≤1 day, (2) no surgery and LOS ≥2 days, (3) surgery, no bowel resection, (4) bowel resection, and (5) ICU admission. RESULTS: Of 323 eligible cases, 87 (26.9%) were VA and 236 (73.1%) VNA. VA-IS cases (median 21 weeks; 24.1% ≤14 weeks) were significantly younger than VNA-IS cases (median 28 weeks, 7.2% ≤14 weeks). Cases 0-≤14 weeks of age were significantly more likely than cases ≥25 weeks to require bowel resection (relative risk ratio 4.6, 95% CI, 1.48-14.3). This effect was not associated with RV. After adjustment for age and sex, VA-IS was not significantly overrepresented in severity levels 2-5; adjusted RRR of 1.37 (95% CI: 0.61-3.11) for bowel resection in cases 0-≤14 weeks of age. CONCLUSIONS: IS was uncommon but significantly more severe under 14 weeks of age. After adjustment for age and sex, IS severity was not related to RV.

Lymphatic filariasis in 2016 in American Samoa: Identifying clustering and hotspots using non-spatial and three spatial analytical methods.

BACKGROUND: American Samoa completed seven rounds of mass drug administration from 2000-2006 as part of the Global Programme to Eliminate Lymphatic Filariasis (LF). However, resurgence was confirmed in 2016 through WHO-recommended school-based transmission assessment survey and a community-based survey. This paper uses data from the 2016 community survey to compare different spatial and non-spatial methods to characterise clustering and hotspots of LF. METHOD: Non-spatial clustering of infection markers (antigen [Ag], microfilaraemia [Mf], and antibodies (Ab [Wb123, Bm14, Bm33]) was assessed using intra-cluster correlation coefficients (ICC) at household and village levels. Spatial dependence, clustering and hotspots were examined using semivariograms, Kulldorf's scan statistic and Getis-Ord Gi* statistics based on locations of surveyed households. RESULTS: The survey included 2671 persons (750 households, 730 unique locations in 30 villages). ICCs were higher at household (0.20-0.69) than village levels (0.10-0.30) for all infection markers. Semivariograms identified significant spatial dependency for all markers (range 207-562 metres). Using Kulldorff's scan statistic, significant spatial clustering was observed in two previously known locations of ongoing transmission: for all markers in Fagali'i and all Abs in Vaitogi. Getis-Ord Gi* statistic identified hotspots of all markers in Fagali'i, Vaitogi, and Pago Pago-Anua areas. A hotspot of Ag and Wb123 Ab was identified around the villages of Nua-Seetaga-Asili. Bm14 and Bm33 Ab hotspots were seen in Maleimi and Vaitogi-Ili'ili-Tafuna. CONCLUSION: Our study demonstrated the utility of different non-spatial and spatial methods for investigating clustering and hotspots, the benefits of using multiple infection markers, and the value of triangulating results between methods.

How have governments supported citizens stranded abroad due to COVID-19 travel restrictions? A comparative analysis of the financial and health support in eleven countries.

BACKGROUND: In response to the continuing threat of importing novel coronavirus disease (COVID-19), many countries have implemented some form of border restriction. A repercussion of these restrictions has been that some travellers have found themselves stranded abroad unable to return to their country of residence, and in need for government support. Our analysis explores the COVID-19-related information and support options provided by 11 countries to their citizens stranded overseas due to travel restrictions. We also examined the quality (i.e., readability, accessibility, and useability) of the information that was available from selected governments' web-based resources. METHODS: Between June 18 to June 30, 2021, COVID-19-related webpages from 11 countries (Australia, New Zealand, Fiji, Canada, United States of America (USA), United Kingdom (UK), France, Spain, Japan, Singapore, and Thailand) were reviewed and content relating to information and support for citizens stuck overseas analysed. Government assistance-related data from each webpage was extracted and coded for the following themes: travel arrangements, health and wellbeing, finance and accommodation, information needs, and sources. Readability was examined using the Simplified Measure of Gobbledygook (SMOG) and the Flesch Kincaid readability tests; content 'accessibility' was measured using the Web Content Accessibility Guidelines (WCAG) Version 2.1; and content 'usability' assessed using the usability heuristics for website design tool. RESULTS: Ninety-eight webpages from 34 websites were evaluated. No country assessed covered all themes analysed. Most provided information and some level of support regarding repatriation options; border control and re-entry measures; medical assistance; and traveller registration. Only three countries provided information or support for emergency housing while abroad, and six provided some form of mental health support for their citizens. Our analysis of the quality of COVID-19-related information available on a subset of four countries' websites found poor readability and multiple accessibility and usability issues. CONCLUSION: This study uniquely analyses government support for citizens stuck abroad during the COVID-19 pandemic. With large variance in the information and services available across the countries analysed, our results highlight gaps, inconsistencies, and potential inequities in support available, and raise issues pertinent to the quality, accessibility, and usability of information. This study will assist policymakers plan and communicate comprehensive support packages for citizens stuck abroad due to the COVID-19 situation and design future efforts to prepare for global public health emergencies.

Potential use of antibodies to provide an earlier indication of lymphatic filariasis resurgence in post-mass drug ad ministration surveillance in American Samoa.

BACKGROUND: Under the Global Programme to Eliminate Lymphatic Filariasis (LF), American Samoa conducted 7 rounds of mass drug administration (MDA) between 2000 and 2006. The territory passed transmission assessment surveys (TASs) in 2011 (TAS-1) and 2015 (TAS-2). In 2016, the territory failed TAS-3, indicating resurgence. This study aims to determine if antibodies (Abs) may have provided a timelier indication of LF resurgence in American Samoa. METHODS: We examined school-level antigen (Ag) and Ab status (presence/absence of Ag- and Ab-positive children) and prevalence of single and combined Ab responses to Wb123, Bm14, and Bm33 Ags at each TAS. Pearson chi-square test and logistic regression were used to examine associations between school-level Ab prevalence in TAS-1 and TAS-2 and school-level Ag status in TAS-3. RESULTS: Schools with higher prevalence of Wb123 Ab in TAS-2 had higher odds of being Ag-positive in TAS-3 (odds ratio [OR] 24.5, 95% confidence interval [CI] 1.2-512.7). Schools that were Ab-positive for WB123 plus Bm14, Bm33, or both Bm14 and Bm33 in TAS-2 had higher odds of being Ag-positive in TAS-3 (OR 16.0-24.5). CONCLUSION: Abs could provide earlier signals of resurgence and enable a timelier response. The promising role of Abs in surveillance after MDA and decision making should be further investigated in other settings.

Expert perspectives on priorities for supporting health security in the Pacific region through health systems strengthening.

The COVID-19 pandemic has reiterated the interdependence of health security and health systems, and the need for resilient health systems to prevent large-scale impacts of infectious disease outbreaks and other acute public health events. Three years into the COVID-19 pandemic has led to discussions on how to "build back better", making it important to identify lessons to strengthen health systems and prevent future shocks from health security threats. Limited data exist on effective implementable initiatives, especially for the Pacific region. We explored the perceptions of a selection of experts with field experience in the Pacific region to identify and prioritise areas for future health system investments that strengthen health security. We conducted a qualitative cross-sectional study, collecting data using four focus group discussions. We analysed the data using a content analysis of notes recorded from each of the sessions. There were 24 participants, representing 15 research and academic institutions, nongovernment agencies, UN agencies and government as well as independent consultants. All were health sector stakeholders with field experience in the Pacific region and expertise in either health systems or health security. The analysis revealed four areas to prioritise future efforts, namely workforce development, risk communication, public health surveillance and laboratory capacity. A fifth theme, localisation, was identified as a cross cutting theme that should be applied to implementation of other identified priority areas. These findings provide a starting point to apply in practice this relatively new concept, of targeted health systems strengthening for health security development, in the Pacific. Evaluation of these initiatives will strengthen knowledge on the value of integrating these two concepts.

Development of the COVID-19 Real-Time Information System for Preparedness and Epidemic Response (CRISPER), Australia.

Accurate and current information has been highlighted across the globe as a critical requirement for the COVID-19 pandemic response. To address this need, many interactive dashboards providing a range of different information about COVID-19 have been developed. A similar tool in Australia containing current information about COVID-19 could assist general practitioners and public health responders in their pandemic response efforts. The COVID-19 Real-time Information System for Preparedness and Epidemic Response (CRISPER) has been developed to provide accurate and spatially explicit real-time information for COVID-19 cases, deaths, testing and contact tracing locations in Australia. Developed based on feedback from key users and stakeholders, the system comprises three main components: (1) a data engine; (2) data visualization and interactive mapping tools; and (3) an automated alert system. This system provides integrated data from multiple sources in one platform which optimizes information sharing with public health responders, primary health care practitioners and the general public.

Sex and Gender in COVID-19 Vaccine Research: Substantial Evidence Gaps Remain.

Since the start of the COVID-19 pandemic there has been a global call for sex/gender-disaggregated data to be made available, which has uncovered important findings about COVID-19 testing, incidence, severity, hospitalisations, and deaths. This mini review scopes the evidence base for efficacy, effectiveness, and safety of COVID-19 vaccines from both experimental and observational research, and asks whether (1) women and men were equally recruited and represented in vaccine research, (2) the outcomes of studies were presented or analysed by sex and/or gender, and (3) there is evidence of sex and/or gender differences in outcomes. Following a PubMed search, 41 articles were eligible for inclusion, including seven randomised controlled trials (RCTs), 11 cohort studies, eight cross-sectional surveys, eight routine surveillance studies, and seven case series. Overall, the RCTs contained equal representation of women and men; however, the observational studies contained a higher percentage of women. Of 10 studies with efficacy data, only three (30%) presented sex/gender-disaggregated results. Safety data was included in 35 studies and only 12 (34%) of these presented data by sex/gender. For those that did present disaggregated data, overall, the majority of participants reporting adverse events were women. There is a paucity of reporting and analysis of COVID-19 vaccine data by sex/gender. Research should be designed in a gender-sensitive way to present and, where possible analyse, data by sex/gender to ensure that there is a robust and specific evidence base of efficacy and safety data to assist in building public confidence and promote high vaccine coverage.