The management of the COVID-19 pandemic has been shown to be critical for reducing its dramatic effects. Social sensing can analyse user-contributed data posted daily in social-media services, where participants are seen as Social Sensors. Individually, social sensors may provide noisy information. However, collectively, such opinion holders constitute a large critical mass dispersed everywhere and with an immediate capacity for information transfer. The main goal of this article is to present a novel methodological tool based on social sensing, called COVIDSensing. In particular, this application serves to provide actionable information in real time for the management of the socio-economic and health crisis caused by COVID-19. This tool dynamically identifies socio-economic problems of general interest through the analysis of people’s opinions on social networks. Moreover, it tracks and predicts the evolution of the COVID-19 pandemic based on epidemiological figures together with the social perceptions towards the disease. This article presents the case study of Spain to illustrate the tool.

Los autores declaran no tener conflictos de interés.

Short oral presentation abstractstransplacental IgG transfer rate (TPTR) in 57 mother/neonate dyads with maternal COVID-19 infection in pregnancy. Methods: 57 women with a COVID-19 infection in pregnancy proven by positive RT-PCR in a nasopharyngeal swab were included in this prospective cohort study. At birth, a venous blood sample was obtained from the mother. Cord blood was taken from the umbilical cord at childbirth after cord clamping. Commercially available high-throughput COVID-19 immunoassays were used for quantitative detection of IgG antibody against COVID-19 spike protein (Liasion Xl, Diasorine). Results: 21 women showed seroconversion at delivery, 36 women had no COVID-19 IgG antibodies in maternal or cord blood at delivery. A lack of antibodies was associated with a short infection-to-delivery interval (<21 days) or asymptomatic or mild infection. Median gestational age at delivery was 39.1 (range 33.4-42.0) weeks, median infection-to-delivery interval was 131 (range 33-261) days, including women in all trimesters. The transplacental transfer ratio of IgG was 139% (range 56-200%). There was positive correlation between the infection-to-delivery interval and the TPTR. The pulsatility index in the uterine arteries (PI) and the maternal body-mass-index (BMI) were negatively correlated with the TPTR. Conclusions: COVID-19 IgG antibodies after COVID-19 infection in pregnancy seem to wane rather rapidly. Asymptomatic or mild infection is often associated with a lack of maternal antibodies at delivery leading to a missing passive immunity of the newborn. Several factors (e.g. PI in the uterine arteries, maternal BMI and the infection-to-delivery interval) might influence the transplacental transfer of COVID-19 specific antibodies but need to be evaluated in further larger cohort studies.