SARS-CoV-2 Seroprevalence Following a Large-Scale Vaccination Campaign in Portugal: Results of the National Serological Survey, September - November 2021.

INTRODUCTION: Following a COVID-19 mass vaccination campaign, it is important to evaluate the population level of SARS-CoV-2 antibodies. The aim of this study was to estimate the seroprevalence rate of SARS-CoV-2 specific antibodies acquired due to infection or vaccination in the Portuguese population. MATERIAL AND METHODS: The National Serological Survey (third wave - ISN3COVID-19) is a cross-sectional nationwide epidemiological study developed on a sample of 4545 Portuguese residents aged one year or older, between the 28th September 2021 and the 19th November 2021. The SARS-CoV-2 anti-nucleoprotein and anti-spike IgG antibody levels were determined in serum samples using Abbott Chemiluminescent Microparticle Immunoassays. Seroprevalence estimates were stratified by age group, sex, administrative region and self-reported chronic conditions. Medians and respective 95% confidence intervals were used to describe the distribution of SARS-CoV-2 specific antibodies in specific population subgroups. RESULTS: The total seroprevalence rate of SARS-CoV-2 was 86.4% (95% CI: 85.2% to 87.6%). A higher seroprevalence rate was estimated for women (88.3%), 50 to 59 years-old (96.5%) and in those with two or more self-reported chronic conditions (90.8%). A higher IgG (anti-Spike) concentration was observed in individuals vaccinated with the booster dose (median = 1 2601.3 AU/mL; 95% CI: 4127.5 to 19 089.1). CONCLUSION: There was a significant increase in SARS-CoV-2 seroprevalence following the mass vaccination campaign in Portugal. It is important to continue to monitor the distribution of specific SARS-COV-2 antibody at the population level to further inform public health policies.

SARS-CoV-2 seroprevalence in Portugal following the third epidemic wave: results of the second National Serological Survey (ISN2COVID-19).

BACKGROUND: Integrated approaches to surveillance of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection are important for public health actions. The 2nd National Serological Survey (ISN2COVID-19) aimed to characterize the extent of SARS-CoV-2 infection and vaccine-induced response in the Portuguese population following the third epidemic wave and the launch of the vaccination campaign. METHODS: A cross-sectional study was performed using data on 8463 Portuguese 1-79 years of age, collected in February and March, 2021. SARS-CoV-2 IgM and IgG (anti-nucleoprotein and anti-spike) antibodies were determined in serum samples using Abbott Architect chemiluminescent microparticle assays. Post-infection and vaccine-induced seroprevalence with 95% confidence intervals (95%CI) were estimated in the overall sample and stratified by population characteristics. RESULTS: The estimated seroprevalence was 15.5% (95%CI:14.6-16.5%), of which 13.5% (95%CI: 12.6-14.4%) was attributable to natural infection and 2.0% (95%CI:1.7-2.4%) to vaccination. The lowest seroprevelence was observed in persons aged 70-79 years (8.9% 95%CI:6.8-11.6), while seroprevalence in children (14.3%; 95%CI:11.5-17.6%) and adolescents (12.9%; 95%CI:10.5-15.7%) was similar to that of persons aged between 20 and 69 years. Of seropositive individuals, 22.6% (95%CI:19.7-25.9%) did not report any symptoms in 6 months prior to interview. Of persons with completed vaccination (2-doses), 98.6% (95%CI: 93.0-99.7%) had specific IgG (anti-S) antibodies. CONCLUSIONS: After the third epidemic wave, the post-infection SARS-CoV-2 seroprevalence was 1.7 times higher than the cumulative incidence based on PCR-testing, but was higher (2.7 times) in children may be due to the high proportion of asymptomatic and mild infections.

Tuberculin skin test and predictive host factors for false-negative results in patients with pulmonary and extrapulmonary tuberculosis.

INTRODUCTION: Tuberculin skin test (TST) has been the standard test for screening for Mycobacterium tuberculosis infection for decades. Identifying persons with latent tuberculosis infection (LTBI) is crucial, as they constitute a reservoir that sustains the global tuberculosis (TB) epidemic. However, different factors, such as HIV infection, can lower the sensitivity of the test. OBJECTIVES: The aim of this study was to determine the TST sensitivity in active TB patients and to ascertain risk factors that could be associated with false-negative results. METHODS: Retrospective cohort study of all active TB notifications with a TST result (n = 8833), from 2008 to 2015. TST results were interpreted using a 5 mm and 10 mm cutoff. Bivariate and multivariate logistic regression analysis were used to evaluate the association of sociodemographic and clinical factors with false-negative TST results and to develop predictive risk models. RESULTS: TST presented an overall sensitivity of 63.8% (5 mm) and 56.1% (10 mm). HIV infection was the risk factor with the strongest association with false-negative results (aOR 4.65-5 mm; aOR 5.05-10 mm). Other factors such as chronic renal failure (CRF) (aOR 1.55-5 mm; aOR 1.73-10 mm), alcohol abuse (aOR 1.52-5 mm; aOR 1.31-10 mm), drug abuse (aOR 1.90-5 mm; aOR 1.76-10 mm) or age ≥65 years (OR 1.69-5 mm and 10 mm) were also associated with a probability of false-negative results. CONCLUSION: These results highlight the importance of knowing which factors influence TST results, such as HIV status, substance abuse or age, thus improving its usefulness as a screening method for LTBI.

Induced pluripotent stem cells, a giant leap for mankind therapeutic applications.

Induced pluripotent stem cells (iPSC) technology has propelled the field of stem cells biology, providing new cells to explore the molecular mechanisms of pluripotency, cancer biology and aging. A major advantage of human iPSC, compared to the pluripotent embryonic stem cells, is that they can be generated from virtually any embryonic or adult somatic cell type without destruction of human blastocysts. In addition, iPSC can be generated from somatic cells harvested from normal individuals or patients, and used as a cellular tool to unravel mechanisms of human development and to model diseases in a manner not possible before. Besides these fundamental aspects of human biology and physiology that are revealed using iPSC or iPSC-derived cells, these cells hold an immense potential for cell-based therapies, and for the discovery of new or personalized pharmacological treatments for many disorders. Here, we review some of the current challenges and concerns about iPSC technology. We introduce the potential held by iPSC for research and development of novel health-related applications. We briefly present the efforts made by the scientific and clinical communities to create the necessary guidelines and regulations to achieve the highest quality standards in the procedures for iPSC generation, characterization and long-term preservation. Finally, we present some of the audacious and pioneer clinical trials in progress with iPSC-derived cells.