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The COVID-19 pandemic has precipitated a global crisis, with more than 1,430,000 confirmed cases and more than 85,000 confirmed deaths globally as of 9 April 2020.sup.1-4. Mitigation and suppression of new infections have emerged as the two predominant public health control strategies.sup.5. Both strategies focus on reducing new infections by limiting human-to-human interactions, which could be both socially and economically unsustainable in the long term. We have developed and analyzed an epidemiological intervention model that leverages serological tests.sup.6,7 to identify and deploy recovered individuals.sup.8 as focal points for sustaining safer interactions via interaction substitution, developing what we term 'shield immunity' at the population scale. The objective of a shield immunity strategy is to help to sustain the interactions necessary for the functioning of essential goods and services.sup.9 while reducing the probability of transmission. Our shield immunity approach could substantively reduce the length and reduce the overall burden of the current outbreak, and can work synergistically with social distancing. The present model highlights the value of serological testing as part of intervention strategies, in addition to its well-recognized roles in estimating prevalence.sup.10,11 and in the potential development of plasma-based therapies.sup.12-15. A new study models the potential effects of preferentially deploying recovered individuals, who are seropositive for anti-SARS-CoV-2 antibodies, into the community to reduce the number of interactions between susceptible and infected people, thereby limiting transmission of the virus., Author(s): Joshua S. Weitz [sup.1] [sup.2] [sup.3] , Stephen J. Beckett [sup.1] , Ashley R. Coenen [sup.2] , David Demory [sup.1] , Marian Dominguez-Mirazo [sup.1] [sup.4] , Jonathan Dushoff [sup.5] [...]

Communicating information about health risks empowers individuals to make informed decisions. To identify effective communication strategies, we manipulated the specificity, self-relevance, and emotional framing of messages designed to motivate information seeking about COVID-19 exposure risk. In Study 1 (N = 221,829), we conducted a large-scale social media field study. Using Facebook advertisements, we targeted users by age and political attitudes. Episodic specificity drove engagement: Advertisements that contextualized risk in specific scenarios produced the highest click-through rates, across all demographic groups. In Study 2, we replicated and extended our findings in an online experiment (N = 4,233). Message specificity (but not self-relevance or emotional valence) drove interest in learning about COVID-19 risks. Across both studies, we found that older adults and liberals were more interested in learning about COVID-19 risks. However, message specificity increased engagement across demographic groups. Overall, evoking specific scenarios motivated information seeking about COVID-19, facilitating risk communication to a broad audience. General Audience Summary: Throughout the COVID-19 pandemic, individuals have weighed risks and benefits when making choices about everyday activities. Learning about the current local risk of COVID-19 exposure is important for making informed decisions. Social media can be a platform for rapidly disseminating health information, but it can also contribute to misinformation and confirmation bias. Here, we tested strategies for risk communication on social media, targeting users by age and political attitudes. In Study 1, we used Facebook advertisements to motivate users to learn about COVID-19 exposure risk. Users who clicked on an ad were directed to interactive risk assessment tools on a public website. We varied the specificity of the advertisements by describing national ("in the United States"), local ("in your area"), or scenario ("at your favorite restaurant") risks. We also manipulated emotional valence by using positive ("stay safe and healthy") or negative ("avoid danger and illness") language. Specificity drove engagement: In all demographic groups, users were the most likely to click on scenario ads. In Study 2, we replicated and extended our findings in a sample of paid participants. In addition to varying the specificity and valence of the ads, we manipulated self-relevance (e.g., "a restaurant" vs. "your favorite restaurant") and tested an alternative scenario (grocery store instead of restaurant). Consistent with Study 1, specificity (but not valence or self-relevance) drove interest in learning about COVID-19 risk. In both studies, we also found that older adults and liberals were more interested in COVID-19 information, whereas conservatives were less engaged and more likely to feel angry or disgusted. However, scenario ads reliably increased engagement across demographic groups. Overall, we found that evoking specific scenarios motivated information seeking about COVID-19 risks. Health messages with improved specificity can be readily disseminated on social media, reaching a broad audience to support public health goals. [ABSTRACT FROM AUTHOR]

The rapid detection of pesticide residues in wheat has become a top food security priority. A solvent-free headspace solid-phase microextraction (HS-SPME) has been evaluated for rapid screening of organophosphorus pesticide (OPP) residues in wheat with high sensitivity. Individual wheat samples (1.7 g), spiked with 10 OPPs, were placed in a 4 mL sealed amber glass vial and heated at 60°C for 45 min. During this time, the OPP residues were extracted with a 50 μm/30 μm divinylbenzene (DVB)/carboxen (CAR)/plasma desorption mass spectroscopy polydimethylsiloxane (PDMS) fiber from the headspace above the sample. The fiber was then removed and injected into the GC injection port at 250°C for desorption of the extracted chemicals. The multiple residues were identified by a GC mass spectrometer detector (GC-MSD) and quantified with a GC flame photometric detector (GC-FPD). Seven spiked levels of 10 OPPs on wheat were analyzed. The GC responses for a 50 μm/30 μm DVB/CAR/ PDMS fiber increased with increasing spiking levels, yielding significant (R² > 0.98) linear regressions. The lowest LODs of the multiple pesticide standards were evaluated under the conditions of the validation study in a range of levels from 0 (control) to 100 ng of pesticide residue per g of wheat that separated on a low-polar GC capillary column (Agilent DB-35UI). The results of the HS-SPME method were compared with the QuEChERS AOAC 2007.01 method and they showed several advantages over the latter. These included improved sensitivity, selectivity, and simplicity. [ABSTRACT FROM AUTHOR]

Bivalent COVID-19 booster vaccines, developed to protect against both ancestral and Omicron BA.4/BA.5 variants, are recommended to increase protection against SARS-CoV-2 infection and severe disease* (1,2). However, relatively few eligible U.S. adults have received a bivalent booster dose (3), and reasons for low coverage are unclear. An opt-in Internet survey of 1,200 COVID-19-vaccinated U.S. adults was conducted to assess reasons for receiving or not receiving a bivalent booster dose. Participants could select multiple reasons from a list of suggested reasons to report why they had or had not received a bivalent booster dose. The most common reasons cited for not receiving the bivalent booster dose were lack of awareness of eligibility for vaccination (23.2%) or of vaccine availability (19.3%), and perceived immunity against infection (18.9%). After viewing information about eligibility and availability, 67.8% of participants who had not received the bivalent booster dose indicated that they planned to do so; in a follow-up survey 1 month later, 28.6% of these participants reported having received the dose. Among those who had planned to receive the booster dose but had not yet done so, 82.6% still intended to do so. Participants who had still not received the booster dose most commonly reported being too busy to get vaccinated (35.6%). To help increase bivalent booster dose coverage, health care and public health professionals should use evidence-based strategies to convey information about booster vaccination recommendations and waning immunity (4), while also working to increase convenient access., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. Joshua S. Weitz reports that he holds the Tom and Marie Patton Chair in the School of Biological Sciences at Georgia Institute of Technology; the Blaise Pascal Chair of Excellence at the Institute of Biology at École Normale Supérieure (2021–2022); receipt of honorarium in October 2022 for a talk focused on mathematical modeling and COVID-19 response as a University of Maryland Bioscience Days lecturer; and reimbursement for personal expenses for numerous invited lectures on COVID-19 topics in academic settings during 2020–2022. No other potential conflicts of interest were disclosed.