Cardiac Involvement in Patients with Multisystem Inflammatory Syndrome in Children (MIS-C) in Poland.

Multisystem inflammatory syndrome in children (MIS-C) is an immune-mediated complication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Cardiovascular system is commonly involved. Acute heart failure (AHF) is the most severe complication of MIS-C, leading to cardiogenic shock. The aim of the study was to characterise the course of MIS-C with a focus on cardiovascular involvement, based on echocardiographic (echo) evaluation, in 498 children (median age 8.3 years, 63% boys) hospitalised in 50 cities in Poland. Among them, 456 (91.5%) had cardiovascular system involvement: 190 (48.2%) of patients had (most commonly atrioventricular) valvular insufficiency, 155 (41.0%) had contractility abnormalities and 132 (35.6%) had decreased left ventricular ejection fraction (LVEF < 55%). Most of these abnormalities improved within a few days. Analysis of the results obtained from two echo descriptions (a median of 5 days apart) revealed a >10% increase in LVEF even in children with primarily normal LVEF. Lower levels of lymphocytes, platelets and sodium and higher levels of inflammatory markers on admission were significantly more common among older children with contractility dysfunction, while younger children developed coronary artery abnormality (CAA) more often. The incidence of ventricular dysfunction might be underestimated. The majority of children with AHF improved significantly within a few days. CAAs were relatively rare. Children with impaired contractility as well as other cardiac abnormalities differed significantly from children without such conditions. Due to the exploratory nature of this study, these findings should be confirmed in further studies.

COVID-19 mRNA BNT162b2 vaccine immunogenicity among children with a history of paediatric multisystem inflammatory syndrome temporally associated with COVID-19 (PIMS-TS).

We conducted a prospective cohort study of 20 patients with a history of paediatric multisystem inflammatory syndrome temporally associated with COVID-19 (PIMS group, median age seven years, 70% male) and 34 healthy controls without such a history (CONTROL group, median age eight years, 38% male) aged 5-12 years, to assess the immunogenicity of Pfizer-BioNTech COVID-19 mRNA BNT162b2 vaccine (Comirnaty®). Patients received two doses of COVID-19 mRNA BNT162b2 vaccine (10 ug/dose) 21 days apart. Pre-vaccine anti-S SARS-CoV-2 IgG antibodies were measured on the day of the first dose and at the median of 23 days after the second dose. The study was conducted during the COVID-19 wave dominated by the Omicron variant of the virus. Anti-NCP SARS-CoV-2 IgG antibodies were measured twice to evaluate incidents of infection during the study period. Pre-vaccine quantification of both types of antibodies allowed us to differentiate patients into COVID-19 naive and previously infected in order to compare hybrid immunity with vaccine-induced immunity. Before vaccination, anti-S IgG serum geometric mean concentration (GMC) was 61.17 BAU/ml in the PIMS group and 24.97 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.

COVID-19 mRNA BNT162b2 vaccine safety and B-cell and T-cell reactogenicity among children with a history of paediatric multisystem inflammatory syndrome temporally associated with COVID-19 (PIMS-TS) - preliminary study.

To assess the safety of Pfizer-BioNTech COVID-19 mRNA BNT162b2 vaccine (Comirnaty®) among patients with the anamnesis of paediatric inflammatory syndrome temporally associated with COVID-19 (PIMS-TS), we conducted a prospective cohort study of 21 patients with history of PIMS (PIMS group, median age 7.4 years, 71% male) and 71 healthy controls without such an anamnesis (CONTROL group, median age 9.0 years, 39% male) aged 5-18 years. Among them, 85 patients (all PIMS patients and 64 CONTROL patients) completed the two dose schedule of vaccination administered 21 days apart and 7 children in the CONTROL group received a single, age appropriate dose of a COVID-19 mRNA BNT162b2 vaccine during the study period. The frequency and character of reported adverse events (AEs) after each dose and results of flow cytometry (FC) 3 weeks after a second dose were compared between those groups. COVID-19 mRNA BNT162b2 vaccine safety profile was very good and comparable in both groups. No severe AEs were observed. 30% of all patients reported some general AE after any vaccine dose and 46% - some local AE. Frequency of reported AEs did not differ between groups except for local hardening at injection site, more common in PIMS group (20% vs 4% after any vaccine dose, p = 0,02). All AEs were benign, general AEs lasted up to 5 days and localised - up to 6 days after a vaccine dose. COVID-19 mRNA BNT162b2 vaccine did not induce any PIMS-like symptoms in any patient. We did not observe any significant T cells or B cells subset abnormalities in the PIMS group compared to the CONTROL group three weeks after a second dose except for terminally differentiated effector memory T cells that were higher in PIMS group (p < 0.0041). To sum up COVID-19 mRNA BNT162b2 vaccine in children with PIMS-TS was safe. Further studies are required to support our findings.

Takotsubo syndrome as a cardiac manifestation of multisystem inflammatory syndrome in children.

Cases of severe heart damage in patients presenting with multisystem inflammatory syndrome in children are one of the most intriguing phenomena during the coronavirus disease of 2019 pandemic. The pathophysiology of myocardial changes in the course of this syndrome has not been fully understood yet. We present a case of a child with multisystem inflammatory syndrome in children and with cardiac changes corresponding to Takotsubo syndrome.

Pediatric Inflammatory Multisystem Syndrome (PIMS) Did Occur in Poland during Months with Low COVID-19 Prevalence, Preliminary Results of a Nationwide Register.

Pediatric inflammatory multisystem syndrome (PIMS) is a new entity in children, likely associated with previous coronavirus disease 19 (COVID-19) infection. Most of the reports about PIMS come from countries particularly hit by the COVID-19 pandemic. Our aim was to investigate the nature of inflammatory syndromes in Poland (country with low COVID-19 prevalence) and to perceive the emergence of PIMS in our country. On 25 May 2020, we launched a nationwide survey of inflammatory syndromes in children for retrospective (since 4 March 2020) and prospective data collection. Up to 28 July, 39 reported children met the inclusion criteria. We stratified them according to age (<5 and ≥ 5 years old) and COVID-19 status. The majority of children had clinical and laboratory features of Kawasaki disease, probably non-associated with COVID-19. However, children ≥5 years of age had PIMS characteristics, and nine children had COVID-19 confirmation. This is, to our knowledge, the first report of the PIMS register from a country with a low COVID-19 prevalence, and it proves that PIMS may emerge in any area involved in the COVID-19 pandemic. In a context of limited COVID-19 testing availability, other risk factors of PIMS, e.g., older age, should be considered in the differential diagnosis of inflammatory syndromes in children.

HPV vaccine acceptance and hesitancy - lessons learned during 8 years of regional HPV prophylaxis program in Wroclaw, Poland.

In 2019, the WHO has announced that it will intensify efforts to eliminate cervical cancer worldwide by increasing coverage of the HPV (Human Papillomavirus) vaccine. Finding reasons for low HPV vaccine coverage and looking for solutions to address the problem should be the priorities for public health. The municipality of Wroclaw (Poland) attempted to meet the challenge earlier by introducing a Prophylaxis Program against HPV in 2010. The core of the program are educational meetings at schools and free vaccinations offered at GP offices. After five successful years (vaccination coverage >80% fully vaccinated), vaccination uptake declined to 61.8%. A survey was carried out in 2015 to verify the experience concerning the Program among 1360 volunteers. Three groups were surveyed: parents (n = 509), teenage girls (n = 748) and nurses who performed the vaccinations (n = 103). What is noteworthy in the results there are factors that positively influenced vaccine acceptance: education offered within the program; the fact that the vaccinations are offered free of charge and the experience of earlier vaccination. It turned out that fear of side effects and the lack of trust in vaccination effectiveness were the most common reasons for vaccination refusal. Most nurses underestimated their role in building vaccination acceptance and 7.1% of them felt uncertain administrating the vaccination. Conslusions: the vaccination delivery strategy should be reconsidered; interventions to raise the nurses' awareness of their role in building vaccine acceptance should be improved; the 13th year of life is the best moment to offer a vaccination.