DISPATCHESS evere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread rapidly worldwide during 2020-2021, but incidence has been highly variable in different countries and is diffi cult to estimate. In Portugal, which has ≈10.3 million inhabitants, the burden of disease, cases, and deaths was similar to or less than that for neighboring countries during the fi rst wave of the coronavirus disease (COVID-19) pandemic, through September 2020 (Appendix Figure, https://wwwnc.cdc.gov/ EID/article/27/11/21-0636-App1.pdf). However, it is diffi cult to estimate the true extent of SARS-CoV-2 infections in Portugal, although a previous study of clinical patients indicated a seropositivity <2.9% (1). We report a national, cross-sectional, epidemiologic survey that used quota sampling to quantify more accurately the cumulative number of infected persons in Portugal. The StudyWe used a convenience quota sampling, quasi-proportional to the population of Portugal in 9 strata: age group (<18, 18-54, and >55 years of age), each subdivided by population density of place of residence (<60, 60-500, and >500 persons/km 2 ) (Appendix). After a widespread media campaign, we recruited participants by using voluntary registration on a website specifi cally designed for this study. We obtained informed consent from all participants >16 years of age and from legal guardians for participants <18 years of age. The study was approved by the Ethics Committee of the Centro Académico de Medicina de Lisboa (#350/20, July 30, 2020).Blood collections and serologic tests were performed by Centro de Medicina Laboratorial Germano de Sousa (Lisbon, Portugal) by using standard procedures. We determined total antibodies against SARS-CoV-2 by using a chemiluminescent immunoassay test (COV2T; Advia Centaur Siemens, https:// www.siemens-healthineers.com), which targets the spike protein. This antibody test has a sensitivity of 98.1% and a specifi city of 99.9% (2), which we used to correct the seroprevalence estimates by using the Rogan-Gladen estimator (3). We used sample weights and poststratifi ed by sex to adjust the seroprevalence, extrapolating from the strata to the whole population (Appendix Tables 1-4). Participants completed a questionnaire with demographic, clinical, and epidemiologic questions regarding SARS-CoV-2 exposure (Appendix). We use standard statistical analyses to compare results at an α = 0.05 signifi cance.We enrolled 13,398 participants (55.3% women, age range 1-92 years) (Appendix Figure 2). Our sample refl ected approximately the characteristics of the

Here we determined the relative expression of HERV-K and W proviruses in HIV infected and non-infected mothers as well as their respective babies up to 1 year-old. HIV-infected mothers, their babies and uninfected control groups presented expression of both HERV-K and HERV-W with relatively high frequency. While the level of HERV-K expression was similar among groups, the level of HERV-W expression in HIV-infected mothers was four-fold higher than the uninfected mothers from the control group (p < 0.01). HERV-W was down regulated in HIV-exposed babies in comparison to non-exposed babies. To our knowledge, this is the first report of HERV transcriptional activity in babies from 0-1 year-old.