Development of an effective immune response in adults with Down Syndrome after SARS-CoV-2 vaccination

Immune dysregulation in individuals with Down syndrome (DS) leads to an increased risk for hospitalization and death due to COVID-19 and may impair the generation of protective immunity after vaccine administration. The cellular and humoral responses of 55 DS patients who received a complete SARS-CoV-2 vaccination regime at one to three (V1) and six (V2) months were characterised. SARS-CoV-2-reactive CD4+ and CD8+ T lymphocytes with a predominant Th1 phenotype were observed at V1, and increased at V2. Likewise, a sustained increase of SARS-CoV-2-specific circulating Tfh (cTfh) cells was observed one to three months after vaccine administration. Specific IgG antibodies against SARS-CoV-2 S protein were detected in 96% and 98% of subjects at V1 and V2, respectively, though IgG titers decreased significantly between both timepoints. SUMMARYThe work shows the cellular and humoral responses to SARS-CoV-2 vaccination of individuals with Down syndrome (DS) after one to three (V1) and six (V2) months. An effective immune response after six months was observed in 98% of DS individuals.

Evaluation of two RT-PCR techniques for SARS-CoV-2 RNA detection in serum for microbiological diagnosis

Presence of SARS-CoV-2 RNA in serum (viraemia) in COVID-19 patients has been related to poor prognosis and death. The aim of this study was to evaluate the ability of two commercial reverse real-time-PCR (rRT-PCR) kits, cobas(R) SARS-CoV-2 (Cobas(R) test) and TaqPath COVID-19 CE-IVD RT-PCR Kit (Taqpath test), to detect viraemia in COVID-19 patients and their implementation as routine diagnosis in microbiology laboratory. This retrospective cohort study was conducted with 203 adult patients admitted to Hospital Universitario de La Princesa, (89 Intensive Care Unit and 114 ward) with at least one serum sample collected in the first 48 hours from admission. A total 265 serum samples were included for study. Evaluation of both rRT-PCR techniques was performed comparing with the gold standard, a Novel Coronavirus (2019-nCoV) Nucleic Acid Diagnostic Kit; considering at least one target as a positive result. Comparison of Cobas(R) test and Taqpath test with the gold standard method, showed high values of specificity (93.75 and 92.19 respectively) and Positive Predictive Value (92.92 and 99.88 respectively). Nevertheless, sensitivity (53.72 and 73.63 respectively) and Negative Predictive Value (32.53 and 42.99 respectively) were lower; Kappa values were 0.35 for cobas(R) test and 0.56 for Taqpath test. For both techniques, differences of viraemia detection between the ICU and non-ICU patients were significant (p[≤]0.001). Consequently, SARS-CoV-2 viraemia positive results obtained by both rRT-PCR should be considered good tools and may help in handling COVID-19 patients. Moreover, these methods could be easily integrated in the routine laboratory COVID-19 diagnosis and may open new strategies based on an early COVID-19 treatment.