To vaccinate or not to vaccinate - BNT162b2 seroconversion rate and side effects among Polish healthcare workers.

OBJECTIVES: The study aimed to analyze the effect of BNT162b2 vaccination among Polish healthcare workers in terms of serologic response and adverse events. MATERIAL AND METHODS: A questionnaire survey covered data in the period January 1-March 31, 2021 gathered in 2 hospitals in Wielkopolska, Poland. Additionally, serological analysis (SARS-CoV-2 anti-S protein IgG) was performed. RESULTS: A total of 617 medical workers were vaccinated with BNT162b2 (Comirnaty, Pfizer). Data from the questionnaires were received from all of the staff after the first and the second dose. No severe side effects were observed. The most common side effect following the first and second doses of vaccination was pain at the injection site. After the first dose, 3 (1.4 %) women aged 18-55 years, 5 women (3.9 %), and 3 men (8.3 %) aged >55 years had negative SARS-CoV-2 anti-S protein IgG result. After the second dose, all those who agreed to have antibodies tested responded to vaccination with positive SARS-CoV-2 anti-S protein IgG results. CONCLUSIONS: Vaccination tolerance was good in the studied population; no severe side effects were observed. After the second dose, all tested healthcare workers responded to vaccination with antibody production. Int J Occup Med Environ Health. 2022;35(6):761-66.

Immune profile of children diagnosed with multisystem inflammatory syndrome associated with SARS-CoV-2 infection (MIS-C).

Introduction: The pathophysiology of multisystem inflammatory syndrome associated with SARS-CoV-2 infection (MIS-C) remains poorly understood. This study aimed to define peripheral blood immune features in patients with MIS-C. Material and methods: We analyzed seven children diagnosed with MIS-C between April 1 and May 15, 2021, in St. Joseph's Children's Hospital in Poznan (Poland). Results: All patients had elevated inflammatory markers, IgG antibodies against SARS-CoV-2, and lymphopenia with a marked decrease in CD4+ and CD8+ T cells. The majority of CD4+ T cells were naive cells. Almost all (6/7) of the analyzed patients had a higher CD4+/CD8+ T cell ratio than average values. B cells were within the normal range - the majority were non-memory cells. Conclusions: Children with MIS-C do not resemble adults during COVID-19 recovery. The immune profile of the studied patients differs from that of children with Kawasaki disease (KD), but it is similar to that of adults with severe COVID-19. The proposed explanation is a profound lymphopenia caused by SARS-CoV-2 infection - which persists for weeks - as a result leading to uncontrolled inflammation. In COVID-19 patients the T cell level returns to normal after the second week of the disease. Our data suggest that in children prolonged lymphopenia after COVID-19 can be a practical marker for possible MIS-C alert. If there is a continuum from lymphopenia to MIS-C, there is room for screening and prevention. Further studies are needed to determine whether steroid treatment introduced in a child with prolonged lymphopenia could stop the inflammatory process.

Can AI Help Pediatricians? Diagnosing Kawasaki Disease Using DRSA.

The DRSA method (dominance-based rough set approach) was used to create decision-making rules based on the results of physical examination and additional laboratory tests in the differential diagnosis of Kawasaki disease (KD), infectious mononucleosis and S. pyogenes pharyngitis in children. The study was conducted retrospectively. The search was based on the ICD-10 (International Classification of Diseases) codes of final diagnosis. Demographic and laboratory data from one Polish hospital (Poznan) were collected. Traditional statistical methods and the DRSA method were applied in data analysis. The algorithm formed 45 decision rules recognizing KD. The rules with the highest sensitivity (number of false negatives equals zero) were based on the presence of conjunctivitis and CRP (C-reactive Protein) ≥ 40.1 mg/L, thrombocytosis and ESR (Erythrocyte Sedimentation Rate) ≥ 77 mm/h; fair general condition and fever ≥ 5 days and rash; fair general condition and fever ≥ 5 days and conjunctivitis; fever ≥ 5 days and rash and CRP ≥ 7.05 mg/L. The DRSA analysis may be helpful in diagnosing KD at an early stage of the disease. It can be used even with a small amount of clinical or laboratory data.