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Abstract Background Wearing a mask was a crucial component in slowing the COVID-19 pandemic. However, little is known about the intersectionality between mask usage, risk perception, and infection. The purpose of this study was to investigate whether risk perceptions and masking behaviors are associated with contracting SARS-CoV-2 and how contracting SARS-CoV-2 subsequently changes masking behaviors in specific situations. Methods This cohort study utilized survey data from the UC San Diego ZAP COVID-19 study (n = 1,230) to evaluate the risk of contracting SARS-CoV-2 in relation to baseline risk perceptions and masking behaviors in various situations and how contracting SARS-CoV-2 affects subsequent masking behavior. Results We found that more consistent self-reported mask use in indoor public spaces (p = 0.03) and in other people’s houses (p = 0.002) was associated with remaining free of SARS-CoV-2 infection. We also found that contracting SARS-CoV-2 was associated with a subsequent increase in mask use in other people’s houses (p = 0.01). Conclusions Our findings suggest that consistent mask use is correlated with decreased infection and that contracting SARS-CoV-2 may modify mask use behaviors in high-risk situations. These findings may help inform future public health messaging for infectious disease prevention. Trial registration This study has not been previously registered as it is an observational study. There was no pre-registration of the analytic plan for the present study.

BACKGROUND: Immune changes that occur during pregnancy may place pregnant women at an increased risk for severe disease following viral infections like SARS-CoV-2. Whether these immunologic changes modify the immune response to SARS-CoV-2 infection during pregnancy is not well understood. OBJECTIVE: This study aimed to compare the humoral immune response to SARS-CoV-2 infection in pregnant and nonpregnant women. The immune response following vaccination for SARS-CoV-2 was also explored. STUDY DESIGN: In this cohort study, 24 serum samples from 20 patients infected with SARS-CoV-2 during pregnancy were matched by number of days after a positive test with 46 samples from 40 nonpregnant women of reproductive age. Samples from 9 patients who were vaccinated during pregnancy were also examined. Immunoglobulin G and immunoglobulin M levels were measured. Trends in the log antibody levels over time and mean antibody levels were assessed using generalized estimating equations. RESULTS: The median number of days from first positive test to sampling was 6.5 in the pregnant group (range, 3–97) and 6.0 among nonpregnant participants (range, 2–97). No significant differences in demographic or sampling characteristics were noted between the groups. No differences in immunoglobulin G or immunoglobulin M levels over time or mean antibody levels were noted among pregnant and nonpregnant participants following SARS-CoV-2 infection for any of the SARS-CoV-2 antigen targets examined (spike, spike receptor-binding domain, spike N-terminal domain, and nucleocapsid). Participants who were vaccinated during pregnancy had higher immunoglobulin G levels than pregnant patients who tested positive for all SARS-CoV-2 targets except nucleocapsid antibodies (all P

Context: When comparing success rates between treatments, it is more appropriate to structure analyses in terms of equivalence rather than traditional analyses that assess differences. Unfortunately, no studies of elective single blastocyst transfer (eSBT) have been conducted in this manner. Aims: The objective of this study was to assess clinical equivalence of in vitro fertilization success rates among patients undergoing eSBT. Settings and Design: A historical prospective study was conducted at a private fertility center. Methods: Medical records were reviewed to identify patients eligible for eSBT. Equivalency of success rates, defined as no more than a 10% difference based on 95% confidence intervals (CIs), was compared between eSBT (n = 125) and eDBT (n = 213) groups. Results: Using traditional analysis techniques, no differences in pregnancy or live-birth rates were seen (eSBT: 84.6% vs. eDBT: 84.5%, P = 0.99; eSBT: 65.3% vs. eDBT: 72.3%, P = 0.23). The 95% CI around the difference in pregnancy rates ranged from -7.9 to 8.1, suggesting clinically equivalent pregnancy rates. Clinical equivalence was not established for live-births (95% CI = −18.5–4.5). Conclusions: Findings suggest comparable pregnancy rates can be achieved in a clinical setting when utilizing eSBT in good-prognosis patients. Although live-birth rate equivalence was not demonstrated, it is thought the additional complications associated with multiple gestations outweigh the potentially higher live-birth rate. The present study highlights the importance of utilizing equivalence analyses when making statements regarding the similarity of two treatments in reproductive health, rather than relying on superiority analyses alone.

HIV rapid diagnostic tests (RDTs) combined in an algorithm are the current standard for HIV diagnosis in many sub-Saharan African countries, and extensive laboratory testing has confirmed HIV RDTs have excellent sensitivity and specificity. However, false-positive RDT algorithm results have been reported due to a variety of factors, such as suboptimal quality assurance procedures and inaccurate interpretation of results. We conducted HIV serosurveys in seven sub-Saharan African military populations and recorded the frequency of personnel self-reporting HIV positivity, but subsequently testing HIV-negative during the serosurvey. The frequency of individuals who reported they were HIV-positive but subsequently tested HIV-negative using RDT algorithms ranged from 3.3 to 91.1%, suggesting significant rates of prior false-positive HIV RDT algorithm results, which should be confirmed using biological testing across time in future studies. Simple measures could substantially reduce false-positive results, such as greater adherence to quality assurance guidelines and prevalence-specific HIV testing algorithms as described in the World Health Organization's HIV testing guidelines. Other measures to improve RDT algorithm specificity include classifying individuals with weakly positive test lines as HIV indeterminate and retesting. While expansion of HIV testing in resource-limited countries is critical to identifying HIV-infected individuals for appropriate care and treatment, careful attention to potential causes of false HIV-positive results are needed to prevent the significant medical, psychological, and fiscal costs resulting from individuals receiving a false-positive HIV diagnosis.