An Assessment of a Rapid SARS-CoV-2 Antigen Test in Bangladesh.

Early detection of SARS-CoV-2 infection is crucial to prevent its spread. This study aimed to document test sensitivity/specificity, correlation with cycle threshold value from polymerase chain reaction (PCR), fitness-for-use in different populations and settings, and user perspectives that could inform large-scale implementation. In this study, we evaluated the performance of a rapid antigen detection test, BD Veritor, and compared this (and another rapid test, Standard Q) against reverse transcription PCR (RT-PCR) in terms of sensitivity and specificity in 130 symptomatic and 130 asymptomatic adults. In addition, we evaluated the suitability and ease of use of the BD Veritor test in a subsample of study participants (n = 42) and implementers (n = 5). At 95% confidence interval, the sensitivity of the BD Veritor and Standard Q test were 70% and 63% in symptomatic and 87% and 73% in asymptomatic individuals, respectively, regarding positive SARS-CoV-2 RT-PCR results. Overall, the BD Veritor test was 78% sensitive and 99.5% specific compared with RT-PCR irrespective of the cycle threshold. This warrants large field evaluation as well as use of the rapid antigen test for quick assessment of SARS-CoV-2 for containment of epidemics in the country.

Meeting report: 6th Global Forum on Tuberculosis Vaccines, 22–25 February 2022, Toulouse, France

Safe, effective, and accessible vaccines are urgently needed to end tuberculosis (TB) by 2030. The 6th Global Forum on TB Vaccines, convened virtually 22–25 February 2022, was hosted by Toulouse, France, under the high patronage of President Emmanuel Macron, and the patronages of Minister for Solidarity and Health, Olivier Véran, and Minister for Higher Education, Research and Innovation, Frédérique Vidal. The theme for the meeting, "New horizons for TB vaccines”, reflected the changing landscape in which TB vaccine research and development (R&D) is being conducted: TB vaccines advancing into late-stage clinical trials and toward licensure, innovative research toward diversifying the TB vaccine pipeline and developing the next generation of candidates, increasing political, civil society, and community support for TB vaccines, and the ongoing COVID-19 pandemic. In this report, we summarize key themes and findings from the meeting, highlighting progress and gaps in the TB vaccine field.

COVID-19 vaccinology landscape in Africa.

More than two years after the start of COVID-19 pandemic, Africa still lags behind in terms vaccine distribution. This highlights the predicament of Africa in terms of vaccine development, deployment, and sustainability, not only for COVID-19, but for other major infectious diseases that plague the continent. This opinion discusses the challenges Africa faces in its race to vaccinate its people, and offers recommendations on the way forward. Specifically, to get out of the ongoing vaccine shortage trap, Africa needs to diversify investment not only to COVID-19 but also other diseases that burden the population. The continent needs to increase its capacity to acquire vaccines more equitably, improve access to technologies to enable local manufacture of vaccines, increase awareness on vaccines both in rural and urban areas to significantly reduce disease incidence of COVID-19 and as well as other prevalent diseases on the African continent such as HIV and TB. Such efforts will go a long way to reduce the disease burden in Africa.

Evaluation of the Access Bio CareStart rapid SARS-CoV-2 antigen test in asymptomatic individuals tested at a community mass-testing program in Western Massachusetts.

Point-of-care antigen-detecting rapid diagnostic tests (RDTs) to detect Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) represent a scalable tool for surveillance of active SARS-CoV-2 infections in the population. Data on the performance of these tests in real-world community settings are paramount to guide their implementation to combat the COVID-19 pandemic. We evaluated the performance characteristics of the CareStart COVID-19 Antigen test (CareStart) in a community testing site in Holyoke, Massachusetts. We compared CareStart to a SARS-CoV-2 reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) reference, both using anterior nasal swab samples. We calculated the sensitivity, specificity, and the expected positive and negative predictive values at different SARS-CoV-2 prevalence estimates. We performed 666 total tests on 591 unique individuals. 573 (86%) were asymptomatic. There were 52 positive tests by RT-qPCR. The sensitivity of CareStart was 49.0% (95% Confidence Interval (CI) 34.8-63.4) and specificity was 99.5% (95% CI 98.5-99.9). Among positive RT-qPCR tests, the median cycle threshold (Ct) was significantly lower in samples that tested positive on CareStart. Using a Ct ≤ 30 as a benchmark for positivity increased the sensitivity of the test to 64.9% (95% CI 47.5-79.8). Our study shows that CareStart has a high specificity and moderate sensitivity. The utility of RDTs, such as CareStart, in mass implementation should prioritize use cases in which a higher specificity is more important, such as triage tests to rule-in active infections in community surveillance programs.

Performance Evaluation of Lateral Flow Assays for Coronavirus Disease-19 Serology.

The coronavirus disease of 2019 (COVID-19) pandemic, caused by infection with the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has undoubtedly resulted in significant morbidities, mortalities, and economic disruptions across the globe. Affordable and scalable tools to monitor the transmission dynamics of the SARS-CoV-2 virus and the longevity of induced antibodies will be paramount to monitor and control the pandemic as multiple waves continue to rage in many countries. Serologic assays detect humoral responses to the virus, to determine seroprevalence in target populations, or induction of antibodies at the individual level following either natural infection or vaccination. With multiple vaccines rolling out globally, serologic assays to detect anti-SARS-CoV-2 antibodies will be important tools to monitor the development of herd immunity. To address this need, serologic lateral flow assays (LFAs), which can be easily implemented for both population surveillance and home use, will be vital to monitor the evolution of the pandemic and inform containment measures. Such assays are particularly important for monitoring the transmission dynamics and durability of immunity generated by natural infections and vaccination, particularly in resource-limited settings. In this review, we discuss considerations for evaluating the accuracy of these LFAs, their suitability for different use cases, and implementation opportunities.

Systematic Approach to Address Early Pandemic's Diagnostic Unmet Needs.

During the first few months of the global Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) pandemic, the medical research community had to expeditiously develop, select, and deploy novel diagnostic methods and tools to address the numerous testing challenges presented by the novel virus. Integrating a systematic approach to diagnostic selection with a rapid validation protocol in a clinical setting can shorten the timeline to bring new technologies to practice. In response to the urgent need to provide tools for identifying SARS-CoV-2-positive individuals, we developed a framework for assessing technologies against a set of prioritized performance metrics to guide device selection. We also developed and proposed clinical validation frameworks for the rapid screening of new technologies. The rubric described here represents a versatile approach that can be extended to future technology assessments and can be implemented in preparation for future emerging pathogens.

Harmonization of Multiple SARS-CoV-2 Reference Materials Using the WHO IS (NIBSC 20/136): Results and Implications.

Background: There is an urgent need for harmonization between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serology platforms and assays prior to defining appropriate correlates of protection and as well inform the development of new rapid diagnostic tests that can be used for serosurveillance as new variants of concern (VOC) emerge. We compared multiple SARS-CoV-2 serology reference materials to the WHO International Standard (WHO IS) to determine their utility as secondary standards, using an international network of laboratories with high-throughput quantitative serology assays. This enabled the comparison of quantitative results between multiple serology platforms. Methods: Between April and December 2020, 13 well-characterized and validated SARS-CoV-2 serology reference materials were recruited from six different providers to qualify as secondary standards to the WHO IS. All the samples were tested in parallel with the National Institute for Biological Standards and Control (NIBSC) 20/136 and parallel-line assays were used to calculate the relevant potency and binding antibody units. Results: All the samples saw varying levels of concordance between diagnostic methods at specific antigen-antibody combinations. Seven of the 12 candidate materials had high concordance for the spike-immunoglobulin G (IgG) analyte [percent coefficient of variation (%CV) between 5 and 44%]. Conclusion: Despite some concordance between laboratories, qualification of secondary materials to the WHO IS using arbitrary international units or binding antibody units per milliliter (BAU/ml) does not provide any benefit to the reference materials overall, due to the lack of consistent agreeable international unit (IU) or BAU/ml conversions between laboratories. Secondary standards should be qualified to well-characterized reference materials, such as the WHO IS, using serology assays that are similar to the ones used for the original characterization of the WHO IS.

Coronavirus Disease 2019 Diagnostics: Key to Africa's Recovery.

With the coronavirus disease of 2019 (COVID-19) becoming a full-blown outbreak in Africa, coupled with many other challenges faced on the African continent, it is apparent that Africa continues to need diagnostics to enable case identification and recovery to this and future challenges. With the slow vaccination rates across the continent, reliable diagnostic tests will be in demand, likely for years to come. Thus, access to reliable diagnostic tools to detect the severe acute respiratory syndrome of the coronavirus-2 (SARS-CoV-2), the virus responsible for COVID-19, remain a critical pillar to monitor and contain new waves of COVID-19. Increasing the local capacity to manufacture and roll-out vaccines and decentralized COVID-19 testing are paramount for fighting the pandemic in Africa.

Meeting report: Virtual Global Forum on Tuberculosis Vaccines, 20-22 April 2021.

The Global Forum on Tuberculosis (TB) Vaccines was held virtually from 20 to 22 April 2021, marking its 20th anniversary. The Global Forum on TB Vaccines is the world's largest gathering of stakeholders striving to develop new vaccines to prevent TB. The program included more than 60 speakers in 11 scientific sessions, panel discussions, and workshops. It provided an overview of the state of the field, and an opportunity to share the latest research findings, as well as new and innovative approaches to TB vaccine research and development (R&D). This year, it was held against the backdrop of the COVID-19 pandemic and convened researchers, developers, funders, and other stakeholders remotely to discuss opportunities and challenges for TB vaccine R&D in these unprecedented times.