The influence of new SARS-CoV-2 infection during the study around the immunological response to the COVID-19 vaccine The comparison of anti-S IgG response between children who were infected during the study period and those who were not in respect to the previous SARS-CoV-2 status is presented in Table 4

The influence of new SARS-CoV-2 infection during the study around the immunological response to the COVID-19 vaccine The comparison of anti-S IgG response between children who were infected during the study period and those who were not in respect to the previous SARS-CoV-2 status is presented in Table 4. in the CONTROL group, while post-vaccination GMC was 3879.14 BAU/ml and 3704.87 BAU/ml, respectively, and did not significantly differ between the groups. Hybrid immunity (regardless of PIMS history) resulted in a higher concentration of SARS-CoV-2 anti-S antibodies after vaccination. Four (20%) of the children in the PIMS group and 11 (32%) in the CONTROL group got infected with SARS-CoV-2 during the study period, yet all of them asymptomatically, and this event has not significantly altered post-vaccination anti-S titers. In conclusion, COVID-19 vaccination was highly immunogenic in children, including those with a history of PIMS-TS; hybrid immunity overperforms vaccine-induced immunity in terms of serological response in children. However, vaccination effectiveness in preventing SARS-CoV-2 infections in children should be further evaluated. Keywords: Comirnaty, MIS-C, PIMS-TS, COVID-19 vaccination, MIS-V, Pediatric 1.?Introduction Coronavirus disease 2019 (COVID-19) mRNA vaccines turned out to be highly immunogenic for paediatric patients aged 5C12?years, resulting in a response non-inferior to older age groups [1]. Early studies indicated moderate to high efficacy in preventing COVID-19-related symptoms and hospitalisation in this age group [2], [3], [4]. Fewer data are available to assess the effectiveness of vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) contamination per se [4]. Data concerning COVID-19 vaccines in paediatric groups of special concern are similarly sparse. One of those groups is children who had paediatric multisystem inflammatory syndrome temporally associated with COVID-19 (PIMS-TS) [5], [6], [7]. The immune-mediated complication of either symptomatic or asymptomatic SARS-CoV-2 contamination appears in 1:3000 infected (non-vaccinated) children approximately four weeks after contamination [8], [9]. PIMS-TS is usually a hyperinflammatory reaction with cytokine storm, fever, extremely IU1-47 high inflammatory markers, and multisystem presentation features. The Rabbit Polyclonal to MAP3K1 (phospho-Thr1402) signs and symptoms occurring most often are mucocutaneous, from the gastrointestinal tract and cardiovascular system. A IU1-47 significant fraction of children develop acute heart failure and shock, henceforth require intensive care. Immunomodulatory drugs, such as intravenous immunoglobulins (IVIG) and glucocorticosteroids (GCS), are most commonly used for treatment, and most children recover completely within a few weeks [9], [10], [11], [12], [13], [14], [15]. The severity of disease varies depending on geographical area, as well as with time [8], [14], [16], [17]. During PIMS-TS, a vast majority of children have detectable levels of antibodies against SARS-CoV-2, while a smaller portion, up to 20%, have a computer virus antigen or genetic material identifiable in their airways [10], IU1-47 [12], [14]. According to current data, the concentration of anti-SARS-CoV-2 antibodies in children with PIMS is usually higher than in children with SARS-CoV-2 contamination, yet without this complication [18]. It has not been established, however, how long such obtained protection lasts. Advising around the COVID-19 vaccination strategy for children is challenging given the safety concerns (that we have resolved in another arm of the study [19]) and doubts IU1-47 about the beneficial effects of the vaccination. Henceforth, the principal research question for this study was if children with a history of PIMS-TS benefit from the COVID-19 vaccination in terms of immunological response. To this end, we have compared anti-SARS-CoV-2 IgG antibody response to the vaccination between children with a history of PIMS-TS and healthy controls children who never suffered from this IU1-47 syndrome. Data obtained for adults suggest that hybrid immunity, gained from previous contamination and vaccination, outperforms the immunity induced only by vaccination [20], [21], [22]. Corresponding results in children are limited, however. Thus, the second aim of our study was to compare hybrid immunity with purely vaccine-gained immunity in children 5C12?years old. Incidentally, the study was conducted during a rapidly increasing wave of COVID-19 [B1.1.529 Omicron variant was a predominant circulating sublineage [23] in Poland] (Fig. 1 ), therefore we could also observe and evaluate how many children designed new.