SARS-CoV-2 IN CHILDREN & ADOLESCENTS LIVING WITH HIV IN EUROPE & SOUTH AFRICA

Background: Adults living with HIV may have higher risk of SARS-CoV- 2 infection than HIV negative adults. There are no published data on seroprevalence of SARS-CoV-2 in children and adolescents living with HIV (CALWHIV). Method(s): We did a repeat SARS-CoV-2 seroprevalence study in 7 paediatric HIV observational cohorts in 5 countries in the European Pregnancy & Paediatric Infections Cohort Collaboration (EPPICC;Belgium, Greece, Spain, Ukraine, United Kingdom (UK)) and also the Cape Town Adolescent Antiretroviral Cohort (CTAAC), South Africa (SA) (CALWHIV and HIV negative adolescents). Participants gave 2 blood samples for SARS-CoV-2 antibody testing ~6 months apart during routine visits between May 2020 and July 2022, and completed questionnaires on SARS-CoV-2 exposure/infection and vaccine status. Clinical and demographic data were extracted from clinic records. Result(s): Of 906 participants, 53%(477) were female, 89%(803) CALWHIV, median [IQR] age at first visit 17[15-19] years. Most were enrolled in SA (45%, 410/906), UK (23%, 205/906) or Ukraine (18%, 160/906). 85%(767/906) had 2 blood samples and the rest a single sample. For CALWHIV, at time of first sample, 99%(761/765) were on antiretroviral therapy, median CD4 count was 666[478-858] cells/mL, 70%(535/764) had HIV-1 viral load < 50c/mL. Of those with known SARS-CoV-2 vaccine status, 23%(181/773) CALWHIV and 22% (22/100) HIV negative participants received >=1 vaccine dose. 6%(43/762) of CALWHIV had a documented prior SARS-CoV-2 positive PCR (including 2 hospitalised for COVID, neither severe), and 16%(124/762) self-reported previous positive test and/or COVID-19 symptoms, giving a total of 17%(128/762) with any previous infection. Based on serum testing, 63%(562/898) of participants overall were seropositive on at least one sample (55% (269/488) Europe, 67% (205/307) SA CALWHIV, 85% (88/103) SA HIV negative group), and among the unvaccinated subgroup, 53%(408/765) were seropositive (41% (167/412) Europe, 64% (168/263) SA CALWHIV, 81% (73/90) SA HIV negative). Among samples taken prior to or in absence of vaccination, the proportion testing antibody positive increased over time (Figure). Of unvaccinated CALWHIV with >=1 positive result, 17%(52/299) reported any previous SARS-CoV-2 infection. Conclusion(s): Most CALWHIV were SARS-CoV-2 seropositive by mid-2022 despite low vaccine coverage. Fewer had documented or self-reported COVID-19 infection or disease, suggesting most infections were mild or asymptomatic. Seroprevalence of SARS-CoV-2 antibodies in Europe and South Africa, by HIV status and calendar quarter of sampling. Colours indicate dominant variant based on GISAID data for adults and children.

Sentiment Analysis on Twitter About COVID-19 Vaccination in Mexico

This paper conducts a sentiment analysis of Twitter’s posts, between late October 2020 and late April 2021, regarding COVID-19 vaccination campaign in Mexico through several machine learning models such as Logistic Regression, Neuronal Network, Naive Bayes and Support Vector Machine. To prepare data, Natural Language Processing techniques were used such as tokenization, stemming, n-grams and stopwords. The best performance was achieved by Logistic Regression with an accuracy score of 83.42% while classifying tweets according to a positive or negative sense. This work suggests that sentiment analysis with Twitter information allows to witness a relevant part of the public discussion around specific topics. For this study, the tweets analyzed showed a similar behavior to other search and reference electronic tools, such as Google Trends regarding conversation around COVID. In addition, the present analysis allows the classification and tendency of public opinion. Furthermore, this study shows that measuring people’s opinion through machine learning and natural language processing techniques can generate significant benefits for institutions and businesses given that obtaining information on Twitter is less expensive and can be processed and analyzed faster than other opinion analysis techniques such as surveys or focus groups. © 2021, Springer Nature Switzerland AG.