Rapid antigen tests, such as the Abbott BinaxNOW COVID-19 Ag Card (BinaxNOW), offer results more rapidly (approximately 15-30 minutes) and at a lower cost than do highly sensitive nucleic acid amplification tests (NAATs) (1). Rapid antigen tests have received Food and Drug Administration (FDA) Emergency Use Authorization (EUA) for use in symptomatic persons (2), but data are lacking on test performance in asymptomatic persons to inform expanded screening testing to rapidly identify and isolate infected persons (3). To evaluate the performance of the BinaxNOW rapid antigen test, it was used along with real-time reverse transcription-polymerase chain reaction (RT-PCR) testing to analyze 3,419 paired specimens collected from persons aged ≥10 years at two community testing sites in Pima County, Arizona, during November 3-17, 2020. Viral culture was performed on 274 of 303 residual real-time RT-PCR specimens with positive results by either test (29 were not available for culture). Compared with real-time RT-PCR testing, the BinaxNOW antigen test had a sensitivity of 64.2% for specimens from symptomatic persons and 35.8% for specimens from asymptomatic persons, with near 100% specificity in specimens from both groups. Virus was cultured from 96 of 274 (35.0%) specimens, including 85 (57.8%) of 147 with concordant antigen and real-time RT-PCR positive results, 11 (8.9%) of 124 with false-negative antigen test results, and none of three with false-positive antigen test results. Among specimens positive for viral culture, sensitivity was 92.6% for symptomatic and 78.6% for asymptomatic individuals. When the pretest probability for receiving positive test results for SARS-CoV-2 is elevated (e.g., in symptomatic persons or in persons with a known COVID-19 exposure), a negative antigen test result should be confirmed by NAAT (1). Despite a lower sensitivity to detect infection, rapid antigen tests can be an important tool for screening because of their quick turnaround time, lower costs and resource needs, high specificity, and high positive predictive value (PPV) in settings * Specimens were used to perform a limiting-dilution inoculation of Vero CCL-81 cells, and cultures showing evidence of cytopathic effect were tested by real-time RT-PCR for the presence of SARS-CoV-2 RNA. Viral recovery was defined as any culture in which the first passage had an N1 Ct value at least two Ct values lower than the corresponding clinical specimen. † https://www.biorxiv

Two vaccines together are better than one alone Polio is proving difficult to eradicate. Making the choice between administering a live attenuated vaccine orally (Sabin) or an inactivated vaccine (Salk) by injection has been highly controversial. Patients prefer the Sabin vaccine, but it requires many doses to offer immunity. Jafari et al. tested the two vaccines together in northern India. The injected vaccine significantly reduced virus shedding and boosted intestinal mucosal immunity in children already given the oral vaccine. Thus, using both vaccines could help speed the eventual global demise of polio. Science , this issue p. 922

IMPORTANCEAs self-collected home antigen tests become widely available, a better understanding of their performance during the course of SARS-CoV-2 infection is needed. OBJECTIVE To evaluate the diagnostic performance of home antigen tests compared with reverse transcription-polymerase chain reaction (RT-PCR) and viral culture by days from illness onset, as well as user acceptability. DESIGN, SETTING, AND PARTICIPANTS This prospective cohort study was conducted from January to May 2021 in San Diego County, California, and metropolitan Denver, Colorado. The convenience sample included adults and children with RT-PCR-confirmed infection who used self-collected home antigen tests for 15 days and underwent at least 1 nasopharyngeal swab for RT-PCR, viral culture, and sequencing. EXPOSURES SARS-CoV-2 infection. MAIN OUTCOMES AND MEASURES The primary outcome was the daily sensitivity of home antigen tests to detect RT-PCR-confirmed cases. Secondary outcomes included the daily percentage of antigen test, RT-PCR, and viral culture results that were positive, and antigen test sensitivity compared with same-day RT-PCR and cultures. Antigen test use errors and acceptability were assessed for a subset of participants. RESULTS This study enrolled 225 persons with RT-PCR-confirmed infection (median [range] age, 29 [1-83] years; 117 female participants [52%]; 10 [4%] Asian, 6 [3%] Black or African American, 50 [22%] Hispanic or Latino, 3 [1%] Native Hawaiian or Other Pacific Islander, 145[64%] White, and 11 [5%] multiracial individuals) who completed 3044 antigen tests and 642 nasopharyngeal swabs. Antigen test sensitivity was 50% (95% CI, 45%-55%) during the infectious period, 64% (95% CI, 56%-70%) compared with same-day RT-PCR, and 84% (95% CI, 75%-90%) compared with same-day cultures. Antigen test sensitivity peaked 4 days after illness onset at 77% (95% CI, 69%-83%). Antigen test sensitivity improved with a second antigen test 1 to 2 days later, particularly early in the infection. Six days after illness onset, antigen test result positivity was 61% (95% CI, 53%-68%). Almost all (216 [96%]) surveyed individuals reported that they would be more likely to get tested for SARS-CoV-2 infection if home antigen tests were available over the counter. CONCLUSIONS AND RELEVANCEThe results of this cohort study of home antigen tests suggest that sensitivity for SARS-CoV-2 was moderate compared with RT-PCR and high compared with viral culture. The results also suggest that symptomatic individuals with an initial negative home antigen test result for SARS-CoV-2 infection should test again 1 to 2 days later because test sensitivity peaked several days after illness onset and improved with repeated testing.

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The effects of unilateral and bilateral cryptorchidism and castration on serum concentrations of testosterone, FSH and LH in adult male rats were examined. The results provide no evidence for compensatory growth or development of the remaining scrotal testes up to 32 days after unilateral castration, although the scrotal testis of unilaterally cryptorchid rats showed enlargement when compared with those of control rats (P less than 0 - 05) at 32 days. Unilateral treatments had few significant effects on serum hormones, but testosterone was increased on day 4 (P less than 0 - 05) in unilaterally cryptorchid rats and on day 32 (P less than 0 - 05) in unilaterally castrated rats, compared with controls, and FSH levels were higher in unilaterally castrated rats on day 16 (P less than 0 - 05). Bilateral cryptorchidism caused an increase in serum FSH within 4 days (P less than 0 - 05) and in serum LH by 8 days (P less than 0-05) after surgery, with both hormones reaching levels double those found in control rats (P less than 0 - 01) by day 16, while testosterone levels were maintained at or above control values. Bilateral castration resulted in a marked decrease in testosterone levels (P less than 0 - 01) and a sharp increase in serum gonadotrophins. FSH had nearly doubled (P less than 0 - 01) and LH had increased fourfold (P less than 0 - 01) 4 days after castration, their levels reaching 773% (LH) and 287% (FSH) of control values by 32 days (P less than 0 - 01). The observations support the hypothesis of a separate, testosterone-independent feedback system of the testis on the hypophysis.