Ethical considerations for protecting the options of subjects in primary epidemic vaccine trials

Comments on an article by J. T. Monrad (see record 2020-61038-012). Monrad presented several issues about secondary vaccine trials. It lays out the case in which a vaccine has been tested through phases I-III and is being deployed. Subsequently, consideration is being given to conducting 'trials for another vaccine for the pathogen'. Monrad stated: 'In summary, we may say that researchers have strong prima facie reasons not to conduct a secondary vaccine trial.' Monrad discusses several factors meriting careful consideration about the need for developing and testing more than one vaccine: relative efficacy, length of immunity, adverse reactions (reactogenicity), ease of storage and administration, economic and logistical factors. What is not addressed are the ethical duties that exist when there are competing phase III vaccine candidates for COVID- 19. Ethically, a subject is allowed to quit a trial at any time. But how might this work in a vaccine trial with multiple candidates? If someone has received an experimental vaccine, they need to be informed of what to do should they wish to subsequently try an approved vaccine. But will companies and researchers with financial stakes in one vaccine readily disclose other options either initially or mid-trial? If a subject got experimental vaccine, there may be more of a chance of having an adverse immune reaction to an additional vaccine that is approved. So they may not wish to do anything. Thus, as part of all informed consents for phase three trials, participants need to be told that at the time some vaccine is approved, they will be told whether or not they received the test vaccine or the placebo so as to help participants make their decision as to whether to get another approved vaccine or not. (PsycInfo Database Record (c) 2023 APA, all rights reserved)

Considerations for unblinding individual study participants during vaccine trials.

Premature unblinding of individual participants is rarely reported in publications, but such unblinding can disrupt vaccine trials by causing worry and drop-out of other participants or "pseudo unblinding," in which participants or investigators over-interpret certain symptoms as being related to receiving an investigational product. This review summarizes appropriate reasons for unblinding in vaccine trials. Regulatory guidance could be improved by distinguishing guidance for vaccine trials from drug trials, with the recognition that unblinding individual participants in vaccine studies is rarely needed for management of adverse events following immunization.

Exclusion of older adults and immunocompromised individuals in influenza, pneumococcal and COVID-19 vaccine trials before and after the COVID-19 pandemic.

BACKGROUND: Older adults and immunocompromised individulas are often excluded from vaccine trials. AIM: We hypothesised that during the coronavirus disease 2019 (COVID-19) pandemic, the proportion of trials excluding these patients decreased. METHODS: Using the US Food and Drug Administration and and European Medicines Agency search engines, we identified all vaccines approved against pneumococcal disease, influenza (quadrivalent vaccines), and COVID-19 from 2011 to 2021. Study protocols were screened for direct and indirect age exclusion criteria and exclusion of immunocompromised individuals. In addition, we reviewed the studies with no explicit exclusion criteria and investigated the actual inclusion of those individuals. RESULTS: We identified 2024 trial records; 1702 were excluded (e.g., use of other vaccine or risk group); and 322 studies were eligible for our review. Among the pneumococcal and influenza vaccine trials (n = 193), 81 (42%) had an explicit direct age exclusion, and 150 (78%) had an indirect age-related exclusion. In total, 163 trials (84%) trials were likely to exclude older adults. Among the COVID-19 vaccine trials (n = 129), 33 (26%) had direct age exclusion and 82 (64%) had indirect age exclusion; in total, 85 (66%) trials were likely to exclude older adults. Therefore was a 18% decrease in the proportion of trials with age-related exclusion between 2011 and 2021 (only influenza and pneumococcal vaccine trials) and 2020-2021 (only COVID-19 vaccine trials) (p = 0.014). In a sub-analysis assessing observational and randomised trials, the decrease was 25% and 9%, respectively. Immunocompromised individuals were included in 87 (45%) of the pneumococcal and influenza vaccine trials compared with 54 (42%) of the COVID-19 vaccine trials (p = 0.058). CONCLUSIONS: During the COVID-19 pandemic, we found a decrease in the exclusion of older adults from vaccine trials but no significant change in the inclusion of immunocompromised individulas.

Towards the empowerment of public scientific literacy: Presenter(s): Sara Rubinelli, University of Lucerne and Swiss Paraplegic Research, Switzerland

As demonstrated during the Covid pandemic, evaluating health information and identifying mis/disinformation is very demanding for the general public, making informing the public a key action in pandemic response. Nonetheless, this information is grounded in and contains scientific evidence and concepts. It implicitly assumes some level of scientific knowledge to be understood and used in a correct and actionable manner (e.g., knowledge of how a vaccine is tested for safety and efficacy). Thus, the 'scientific literacy' of the general population becomes prominent. The objective of this presentation is to illustrate a model of public scientific literacy. A conceptual review of existing conceptualisations and operationalisations of scientific literacy found in the literature through comparative evaluation, i.e. the models by Norris and Philis, the Science-Technology Society (STS), OECD Pisa, Ying Zhan and Chiappetta et al. Five main components of public scientific literacy are identified as most prominent. Specifically, the model includes knowledge and evaluation skills on the following topics: the concept of 'scientific evidence' versus an opinion (even of an expert);the different types of quantitative and qualitative evidence;how science works as a process to achieve knowledge based on the principle of falsification;the peer-reviewed process for science publication and the ethical standards for scientific work and its implementation. Scientific literacy is the basis of critical thinking and thus of individual and collective decisions and behaviors that are non-ideological and non-stereotypical. Scientific literacy allows dynamic adaptations of behaviors and modifications of beliefs and knowledge transparently and adaptively, which can integrate knowledge advancements and new information as complex phenomena that are progressively better understood and explained. Findings: from this study can inform the development of measurement instruments and interventions for public scientific literacy. Also they are a basis for strengthening institutional communication of evidence-based recommendations. [ FROM AUTHOR] Copyright of Patient Education & Counseling is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

Enhancing Public Health Communication Regarding Vaccine Trials: Design and Development of the Pan-European VACCELERATE Toolkit.

BACKGROUND: The pan-European VACCELERATE network aims to implement the first transnational harmonized and sustainable vaccine trial Volunteer Registry, being a single entry point for potential volunteers of large-scale vaccine trials across Europe. This work exhibits a set of harmonized vaccine trial-related educational and promotional tools for the general public, designed and disseminated by the pan-European VACCELERATE network. OBJECTIVE: This study primarily aimed to design and develop a standard toolkit to increase positive attitudes and access to trustworthy information for better access and increased recruitment to vaccine trials for the public. More specifically, the produced tools are focused on inclusiveness and equity, and are targeting different population groups, including underserved ones, as potential volunteers for the VACCELERATE Volunteer Registry (older individuals, migrants, children, and adolescents). The promotional and educational material is aligned with the main objectives of the Volunteer Registry to increase public literacy and awareness regarding vaccine-related clinical research or trials and trial participation, including informed consent and legal issues, side effects, and frequently asked questions regarding vaccine trial design. METHODS: Tools were developed per the aims and principles of the VACCELERATE project, focusing on trial inclusiveness and equity, and are adjusted to local country-wise requirements to improve public health communication. The produced tools are selected based on the cognitive theory, inclusiveness, and equity of differently aged and underrepresented groups, and standardized material from several official trustworthy sources (eg, COVID-19 Vaccines Global Access; the European Centre for Disease Prevention and Control; the European Patients' Academy on Therapeutic Innovation; Gavi, the Vaccine Alliance; and the World Health Organization). A team of multidisciplinary specialists (infectious diseases, vaccine research, medicine, and education) edited and reviewed the subtitles and scripts of the educational videos, extended brochures, interactive cards, and puzzles. Graphic designers selected the color palette, audio settings, and dubbing for the video story-tales and implemented QR codes. RESULTS: This study presents the first set of harmonized promotional and educational materials and tools (ie, educational cards, educational and promotional videos, extended brochures, flyers, posters, and puzzles) for vaccine clinical research (eg, COVID-19 vaccines). These tools inform the public about possible benefits and disadvantages of trial participation and build confidence among participants about the safety and efficacy of COVID-19 vaccines and the health care system. This material has been translated into several languages and is intended to be freely and easily accessible to facilitate dissemination among VACCELERATE network participant countries and the European and global scientific, industrial, and public community. CONCLUSIONS: The produced material could help fill knowledge gaps of health care personnel, providing the appropriate future patient education for vaccine trials, and tackling vaccine hesitancy and parents' concerns for potential participation of children in vaccine trials.

Inclusionary trials: A review of lessons not learned.

The COVID-19 pandemic revealed weaknesses in the public health infrastructure of the United States, including persistent barriers to engaging marginalized communities towards inclusion in clinical research, including trials. Inclusive participation in clinical trials is crucial for promoting vaccine confidence, public trust, and addressing disparate health outcomes. A long-standing literature describes the value of community-based participatory research (CBPR) in increasing marginalized community participation in research. CBPR emphasizes shared leadership with community members in all phases of the research process including in the planning and implementation, interpretation, and dissemination. Shared leadership between academic and industry with marginalized communities can assist with inclusive participation in vaccine trials and increase public trust in the development of the vaccines and other therapies that are used during public emergencies. Nevertheless, epidemiological and clinical research do not yet have a strong culture of community partnership in the scientific process, which takes time to build and therefore may be difficult to develop and rapidly scale to respond to the pandemic. This article outlines practices that contribute to a lack of inclusive participation and offers steps that trialists and other researchers can take to increase marginalized communities' participation in research. Practices include planning for community engagement during the planning and recruitment phases, having regular dialogues with communities about their priorities, supporting them throughout a study, and navigating complex structural determinants of health. Additionally, we discuss how research institutions can support inclusive practices by reexamining their policies to increase participation in clinical trials and instilling institutional trustworthiness.

A community-partnered approach for diversity in COVID-19 vaccine clinical trials.

Introduction: Communities of color have faced disproportionate morbidity and mortality from COVID-19, coupled with historical underrepresentation in US clinical trials, creating challenges for equitable participation in developing and testing a safe and effective COVID-19 vaccine. Methods: To increase diversity, including racial and ethnic representation, in local Los Angeles County NIH-sponsored Phase 3 SARS-CoV-2 vaccine clinical trials, we used deliberative community engagement approaches to form a Community Consultant Panel (CCP) that partnered with trial research teams. Thirteen members were recruited, including expertise from essential workers, community-based and faith-based organizations, or leaders from racial and ethnic minority communities. Results: Working closely with local investigators for the vaccine studies, the CCP provided critical insight on best practices for community trust building, clinical trial participation, and reliable information dissemination regarding COVID-19 vaccines. Modifying recruitment, outreach, and trial protocols led to majority-minority participants (55%-78%) in each of the three vaccine clinical trials. CCP's input led to cultural tailoring of recruitment materials, changes in recruitment messaging, and supportive services to improve trial accessibility and acceptability (transportation, protocols for cultural competency, and support linkages to care in case of an adverse event). Barriers to clinical trial participation unable to be resolved included childcare, requests for after-hours appointment availability, and mobile locations for trial visits. Conclusion: Using deliberative community engagement can provide critical and timely insight into the community-centered barriers to COVID-19 vaccine trial participation, including addressing social determinants of health, trust, clinical trial literacy, structural barriers, and identifying trusted messenger and reliable sources of information.

Social capital and willingness to participate in COVID-19 vaccine trials: an Italian case-control study.

BACKGROUND: What leads healthy people to enter in a volunteer register for clinical trials? This study aimed to investigate the relationship between the decision to volunteer in clinical trials for a COVID-19 vaccine and social capital, in a sample of healthy volunteers in Italy. Since social capital is characterized by trust, reciprocity, and social and political participation, we claim that it is key in leading individuals to actively take action to protect public health, and to take a risk for the (potential) benefit not only of themselves but for the entire community. METHODS: This study was conducted through the administration of a questionnaire to healthy volunteers registered for a phase 1 clinical trial for a COVID-19 vaccine in the Unit Research Centre of ASST-Monza, in September 2020. The primary purpose of a phase 1 study is to evaluate the safety of a new drug candidate before it proceeds to further clinical studies. To approximate a case-control study, we randomly matched the 318 respondents to healthy volunteers (cases) with 318 people randomly selected by Round 9 of the European Social Survey (controls), using three variables, which we considered to be associated with the decision to volunteer: gender, age, and education level. To execute this matching procedure, we used the "ccmatch" module in STATA. RESULTS: The findings highlight the positive impact of social capital in the choice of healthy individuals to volunteer in COVID-19 vaccine clinical trials. Controlling for possible confounding factors, some exemplary results show that people with a high level of general trust have a greater likelihood of volunteering compared to people with low trust (OR = 2.75, CI = 1.58-4.77); we also found that it is more probable that volunteers are people who have actively taken action to improve things compared with people who have not (for individuals who did three or more actions: OR = 7.54, CI = 4.10-13.86). People who reported voting (OR = 3.91, CI = 1.70-8.99) and participating in social activities more than other people of their age (OR = 2.89, CI = 1.82-4.60) showed a higher probability to volunteer. CONCLUSIONS: Together with the adoption of urgent health measures in response to COVID-19, government policymakers should also promote social capital initiatives to encourage individuals to actively engage in actions aimed at protecting collective health. Our findings make an empirical contribution to the research on vaccines and its intersection with social behaviour, and they provide useful insights for policymakers to manage current and future disease outbreaks and to enhance the enrolment in vaccine trials.

"Ethical considerations for epidemic vaccine trials": Correction

Reports an error in "Ethical considerations for epidemic vaccine trials" by Joshua Teperowski Monrad (Journal of Medical Ethics: Journal of the Institute of Medical Ethics, 2020[Jul], Vol 46[7], 465-469). In the original article, in a section the term 'white' should read 'non-white'. The correction is given in the erratum. (The following of the original article appeared in record 2020-61038-012). Vaccines are a powerful measure to protect the health of individuals and to combat outbreaks such as the COVID-19 pandemic. An ethical dilemma arises when one effective vaccine has been successfully developed against an epidemic disease and researchers seek to test the efficacy of another vaccine for the same pathogen in clinical trials involving human subjects. On the one hand, there are compelling reasons why it would be unethical to trial a novel vaccine when an effective product exists already. First, it is a firm principle of medical ethics that an effective treatment or vaccine should not be withheld from patients if their life may depend on it. Second, since epidemic outbreaks often emerge in settings with less-resourced health systems, there is a pronounced risk that any trial withholding an effective vaccine would disproportionately affect the vulnerable populations that historically have been exploited for biomedical research. Third, clinical trials for novel vaccines may be at odds with efforts to control active outbreaks. On the other hand, it may be justified to conduct a trial for a candidate vaccine if it is expected to have certain advantages compared with the existing product. This essay discusses key factors for comparing vaccines against epidemic pathogens, including immunological, logistical and economic considerations. Alongside a case study of the development of vaccines for Ebola, the essay seeks to establish a general framework that should be expanded and populated by immunologists, epidemiologists, economists and bioethicists, and ultimately could be applied to the case of COVID-19 vaccines. (PsycInfo Database Record (c) 2022 APA, all rights reserved)

RNA-Based COVID-19 vaccine candidates with clinical phase trials in progress

Due to the COVID-19 infection, which was recognized as a global pandemic by the WHO on March 11, 2020, the number of cases and disease-related deaths increases day by day globally. For this reason, antiviral agents used in treatment and vaccines, the most effective weapon in prevention, continue to be the most popular topic of the plan. Several situations are expected to affect the course of the pandemic. The loss of the ability of the virus to mutate and cause disease, the fact that those who become immunized by having the disease in the society reach a critical rate and create social immunity (herd immunity), and the provision of social immunity with effective vaccination can be counted as some of these situations. Candidate vaccines in the clinical phase among RNA-based vaccines: This review aimed to examine COVID-19 vaccine candidates using RNA technology and compile its current data. We used PubMed, Google Scholar, and World Health Organization (WHO) databases. Also, we followed up on the latest news and developments on vaccine companies' websites. Conclusion: Vaccination trials, which started due to the seriousness and urgency of the situation that we are in, continue exceptionally quickly and effectively. As per the WHO>s data on July 9, 2021, there have been 291 vaccine trials, 107 of which are in the clinical phase, and 18 (16%) of the vaccine candidates in the clinical phase are RNA-based vaccines. Also, the number of RNA-based vaccines with ongoing preclinical trials is 2

Shifts in UNAIDS ethics guidance and implications for ethics review of preventive HIV vaccine trials.

INTRODUCTION: A major change in the ethics framework for preventive HIV vaccine trials worldwide is the release of the UNAIDS 2021 ethical considerations in HIV prevention trials. This new guidance comes at an exciting time when there are multiple HIV vaccine efficacy trials in the field. Research Ethics Committees (RECs) or Institutional Review Boards are a most likely audience for these guidelines. Our objective is to highlight shifts in ethics recommendations from the earlier 2012 UNAIDS guidance. DISCUSSION: We review recommendations related to four key issues, namely standard of prevention, post-trial access to safe and effective vaccines, enrolment of adolescents and enrolment of pregnant women. We outline implications and make recommendations for the ethics review process, including suggested lines of inquiry by RECs and responses by applicants. CONCLUSIONS: There have been several shifts in the UNAIDS ethics guidance with implications for HIV vaccine researchers submitting applications for initial ethics review or re-certification, and for RECs conducting such reviews. This review may assist RECs in a more efficient and consistent application of ethics recommendations. However, additional tools and training may further help stakeholders comply with new UNAIDS ethics recommendations during protocol development and ethics review.

Mapping time use in clinical trials for vaccines against emerging infectious diseases.

BACKGROUND: Vaccines are potent tools to prevent outbreaks of emerging infectious diseases from becoming epidemics and need to be developed at an accelerated pace to have any impact on the course of an ongoing epidemic. The aim of this study was to describe time use in the execution of vaccine trials, to identify steps that could be accelerated to improve preparedness and planning for future emerging infectious diseases vaccine trials. METHODS: We used a mixed-methods approach to map time use and process steps that could be accelerated during vaccine trials. Trials for vaccines against infectious diseases registered in three global trial databases reported in the period 2011-2017 were eligible to join the survey. We invited sponsors to contribute data through a predefined structured questionnaire for clinical trial process metrics. Data were stratified by trial phase, disease type (i.e. emerging infectious diseases or not emerging infectious diseases), sponsor type, and continent. Qualitative interviews were conducted with purposively selected sponsors, and thematic analysis of the interview transcripts was performed. RESULTS: Based on data from 155 vaccine trials including 29,071 subjects, 52% were phase I, 23% phase II, and 25% phase III. We found that the regulatory approval, subject enrollment, study execution, and study close-out accounted for most of the cycle time of the vaccine trial process. Cycle times for the regulatory and ethical approvals, contract agreement, site initiation, and study execution were shorter in trials conducted during outbreaks. Qualitative interviews indicated that early engagement of the regulatory and independent ethical committee authorities in planning the vaccine trials was critical for saving time in trial approval. Furthermore, adapting the trial implementation to the reality of the study sites and active involvement of the local investigators during the planning of the trial and protocol writing were stated to be of paramount importance to successful completion of trials at an accelerated pace. CONCLUSION: The regulatory approval, subject recruitment, study execution, and close-out cycle times accounted for most of the vaccine trial time use and are activities that could be accelerated during a vaccine trial planning and implementation. We encourage tracking of key cycle time metrics and facilitating sharing of knowledge across industry and academia, as this may serve to reduce the time from index case detection to access of a vaccine during emerging infectious diseases epidemics.

Factors associated with parents' willingness to enroll their children in trials for COVID-19 vaccination.

The coronavirus disease 2019 (COVID-19) pandemic has taken an unprecedented global toll and vaccination is needed to restore healthy living. Timely inclusion of children in vaccination trials is critical. We surveyed caregivers of children seeking care in 17 Emergency Departments (ED) across 6 countries during the peak of the pandemic to identify factors associated with intent to participate in COVID-19 vaccine trials. Questions about child and parent characteristics, COVID-19 expressed concerns and parental attitudes toward participation in a trial were asked.Of 2768 completed surveys, 18.4% parents stated they would enroll their child in a clinical trial for a COVID-19 vaccine and 14.4% would agree to a randomized placebo-controlled study. Factors associated with willingness to participate were parents agreeing to enroll in a COVID-19 vaccine trial themselves (Odds Ratio (OR) 32.9, 95% Confidence Interval (CI) (21.9-51.2)) having an older child (OR 1.0 (1.0-1.01)), having children who received all vaccinations based on their country schedule (OR 2.67 (1.35-5.71)) and parents with high school education or lower (OR 1.79 (1.18-2.74)). Mothers were less likely to enroll their child in a trial (OR 0.68 (0.47-0.97)). Only one fifth of families surveyed will consider enrolling their child in a vaccine trial. Parental interest in participation, history of vaccinating their child, and the child being older all are associated with parents allowing their child to participate in a COVID vaccine trial. This information may help decision-makers and researchers shape their strategies for trial design and participation engagement in upcoming COVID19 vaccination trials.

Replicability of studies following a dual-criterion design.

Replicability of results is regarded as the corner stone of science. Recent research seems to raise doubts about whether this requirement is generally fulfilled. Often, replicability of results is defined as repeating a statistically significant result. However, since significance may not imply scientific relevance, dual-criterion study designs that take both aspects into account have been proposed and investigated during the last decade. Originally developed for proof-of-concept trials, the design could be appropriate for phase III trials as well. In fact, a dual-criterion design has been requested for COVID-19 vaccine applications by major health authorities. In this article, replicability of dual-criterion designs is investigated. It turns out that the probability to replicate a significant and relevant result can become as low as 0.5. The replication probability increases if the effect estimator exceeds the minimum relevant effect in the original study by an extra amount.

Does a Public Health Crisis Justify More Research with Incarcerated People?

Covid-19 has infected thousands and killed hundreds in prisons, jails, and immigration detention facilities across the United States. Responding to this crisis, leading medical researchers have called for expanding opportunities for people in prison to participate in vaccine trials. These calls, like current regulations, focus on individualized risk assessments around consent, coercion, and harm, while ignoring the unnaturalness of deprivation conditions in U.S. prisons. We need new frameworks of analysis that refocus on structural, rather than individual, risk assessments. Integrating structural perspectives-including skepticism of claims of scarcity, avoidance of representational distortions, and attention to institutional agency-into our existing, overly individualistic frameworks might permit the design of more ethical research projects involving people who are incarcerated. Still, the unnatural deprivations of incarceration might be so great that research subjects might need to be removed from prison entirely in order to ethically participate in research.

Interest in COVID-19 vaccine trials participation among young adults in China: Willingness, reasons for hesitancy, and demographic and psychosocial determinants.

With the demand for rapid COVID-19 vaccine development and evaluation, this paper aimed to describe the prevalence and correlates of willingness to participate in COVID-19 vaccine trials among university students in China. A cross-sectional survey with 1912 Chinese university students was conducted during March and April 2020. Bivariate and multivariate analyses were performed to identify variables associated with willingness to participate. The majority of participants (64.01%) indicated willingness to participate in COVID-19 vaccine trials. Hesitancy over signing informed consent documents, concerns over time necessary for participating in a medical study, and perceived COVID-19 societal stigma were identified as deterrents, whereas lower socioeconomic status, female gender, perception of likely COVID-19 infection during the pandemic, and COVID-19 prosocial behaviors were facilitative factors. Further, public health mistrust and hesitancy over signing informed consent documents had a significant interactive effect on vaccine trial willingness. High standards of ethical and scientific practice are needed in COVID-19 vaccine research, including providing potential participants full and accurate information and ensuring participation free of coercion, socioeconomic inequality, and stigma. Attending to the needs of marginalized groups and addressing psychosocial factors including stigma and public health mistrust may also be important to COVID-19 vaccine development and future uptake.

Optimal symptom combinations to aid COVID-19 case identification: Analysis from a community-based, prospective, observational cohort.

OBJECTIVES: Diagnostic work-up following any COVID-19 associated symptom will lead to extensive testing, potentially overwhelming laboratory capacity whilst primarily yielding negative results. We aimed to identify optimal symptom combinations to capture most cases using fewer tests with implications for COVID-19 vaccine developers across different resource settings and public health. METHODS: UK and US users of the COVID-19 Symptom Study app who reported new-onset symptoms and an RT-PCR test within seven days of symptom onset were included. Sensitivity, specificity, and number of RT-PCR tests needed to identify one case (test per case [TPC]) were calculated for different symptom combinations. A multi-objective evolutionary algorithm was applied to generate combinations with optimal trade-offs between sensitivity and specificity. FINDINGS: UK and US cohorts included 122,305 (1,202 positives) and 3,162 (79 positive) individuals. Within three days of symptom onset, the COVID-19 specific symptom combination (cough, dyspnoea, fever, anosmia/ageusia) identified 69% of cases requiring 47 TPC. The combination with highest sensitivity (fatigue, anosmia/ageusia, cough, diarrhoea, headache, sore throat) identified 96% cases requiring 96 TPC. INTERPRETATION: We confirmed the significance of COVID-19 specific symptoms for triggering RT-PCR and identified additional symptom combinations with optimal trade-offs between sensitivity and specificity that maximize case capture given different resource settings.

SARS-CoV-2 vaccines in advanced clinical trials: Where do we stand?

The ongoing SARS-CoV-2 pandemic has led to the focused application of resources and scientific expertise toward the goal of developing investigational vaccines to prevent COVID-19. The highly collaborative global efforts by private industry, governments and non-governmental organizations have resulted in a number of SARS-CoV-2 vaccine candidates moving to Phase III trials in a period of only months since the start of the pandemic. In this review, we provide an overview of the preclinical and clinical data on SARS-CoV-2 vaccines that are currently in Phase III clinical trials and in few cases authorized for emergency use. We further discuss relevant vaccine platforms and provide a discussion of SARS-CoV-2 antigens that may be targeted to increase the breadth and durability of vaccine responses.

Challenge Trials: What Are the Ethical Problems?

If, as is alleged, challenge trials of vaccines against COVID-19 are likely to save thousands of lives and vastly diminish the economic and social harms of the pandemic while subjecting volunteers to risks that are comparable to kidney donation, then it would seem that the only sensible objection to such trials would be to deny that they have low risks or can be expected to have immense benefits. This essay searches for a philosophical rationale for rejecting challenge trials while supposing that they have huge benefits and relatively low risks. Although it finds some force in objections to challenge trials grounded in the obligations of researchers to limit the harms imposed on some individuals for the benefit of others, it argues that there is no compelling objection to challenge trials of vaccines for COVID-19-if they have the benefits and risks that have been claimed.

Innovative trial designs and analyses for vaccine clinical development.

In the past decades, the world has experienced several major virus outbreaks, e.g. West African Ebola outbreak, Zika virus in South America and most recently global coronavirus (COVID-19) pandemic. Many vaccines have been developed to prevent a variety of infectious diseases successfully. However, several infections have not been preventable so far, like COVID-19, which induces an immediate urgent need for effective vaccines. These emerging infectious diseases often pose unprecedent challenges for the global heath community as well as the conventional vaccine development paradigm. With a long and costly traditional vaccine development process, there are extensive needs in innovative vaccine trial designs and analyses, which aim to design more efficient vaccines trials. Featured with reduced development timeline, less resource consuming or improved estimate for the endpoints of interests, these more efficient trials bring effective medicine to target population in a faster and less costly way. In this paper, we will review a few vaccine trials equipped with adaptive design features, Bayesian designs that accommodate historical data borrowing, the master protocol strategy emerging during COVID-19 vaccine development, Real-World-Data (RWD) embedded trials and the correlate of protection framework and relevant research works. We will also discuss some statistical methodologies that improve the vaccine efficacy, safety and immunogenicity analyses. Innovative clinical trial designs and analyses, together with advanced research technologies and deeper understanding of the human immune system, are paving the way for the efficient development of new vaccines in the future.