The Influence of SARS-CoV-2 Variants B.1.1.7 and B.1.617.2 on a Different Clinical Course and Severity of COVID-19 in Children Hospitalized in 2021 Compared With 2020.

BACKGROUND: This study aimed to analyze the differences in the epidemiologic and clinical characteristics of coronavirus disease 2019 (COVID-19) in children hospitalized in 2021, when the severe acute respiratory syndrome coronavirus 2 variants B.1.1.7 (alpha) and B.1.617.2 (delta) dominated, compared with 2020. METHODS: In this multicenter study based on the pediatric part of the national SARSTer register (SARSTer-PED), we included 2771 children (0-18 years) with COVID-19 diagnosed between March 1, 2020, and December 31, 2021, from 14 Polish inpatient centers. An electronic questionnaire, which addressed epidemiologic and clinical data, was used. RESULTS: Children hospitalized in 2021 were younger compared with those reported in 2020 (mean 4.1 vs. 6.8 years, P = 0 .01). Underlying comorbidities were reported in 22% of the patients. The clinical course was usually mild (70%). A significant difference in the clinical course assessment between 2020 and 2021 was found, with more asymptomatic patients in 2020 and more severely ill children in 2021. In total, 5% of patients were severely or critically ill, including <3% of the participants in 2020 and 7% in 2021. The calculated mortality rate was 0.1% in general and 0.2% in 2021. CONCLUSION: Infections with severe acute respiratory syndrome coronavirus 2 variants alpha and delta lead to a more severe course of COVID-19 with more pronounced clinical presentation and higher fatality rates than infection with an original strain. Most of the children requiring hospitalization due to COVID-19 do not have underlying comorbidities.

Clinical Course and Severity of COVID-19 in 940 Infants with and without Comorbidities Hospitalized in 2020 and 2021: The Results of the National Multicenter Database SARSTer-PED.

This study aimed to analyze the differences in severity and clinical characteristics of COVID-19 in infants hospitalized in Poland in 2021, when the dominance of variants of concern (VOCs) alpha and delta was reported, compared to 2020, when original (wild) SARS-CoV-2 was dominant (III-IV vs. I-II waves of the pandemic, respectively). In addition, the influence of the presence of comorbidities on the clinical course of COVID-19 in infants was studied. This multicenter study, based on the pediatric part of the national SARSTer database (SARSTer-PED), included 940 infants with COVID-19 diagnosed between March 1, 2020, and December 31, 2021, from 13 Polish inpatient centers. An electronic questionnaire, which addressed epidemiological and clinical data, was used. The number of hospitalized infants was significantly higher in 2021 than in 2020 (651 vs. 289, respectively). The analysis showed similar lengths of infant hospitalization in 2020 and 2021, but significantly more children were hospitalized for more than 7 days in 2020 (p < 0.009). In both analyzed periods, the most common route of infection for infants was household contact. There was an increase in the percentage of comorbidities, especially prematurity, in children hospitalized in 2021 compared to 2020. Among the clinical manifestations, fever was predominant among children hospitalized in 2021 and 2020. Cough, runny nose, and loss of appetite were significantly more frequently observed in 2021 (p < 0.0001). Severe and critical conditions were significantly more common among children with comorbidities. More infants were hospitalized during the period of VOCs dominance, especially the delta variant, compared to the period of wild strain dominance, even though indications for hospitalization did not include asymptomatic patients during that period. The course of COVID-19 was mostly mild, characterized mainly by fever and respiratory symptoms. Comorbidities, particularly from the cardiovascular system and prematurity, were associated with a more severe course of the disease in infants.

COVID-19 infections in infants.

The study aimed to analyse the clinical course of COVID-19 in 300 infants, selected from 1283 children diagnosed with COVID-19 between March and December 2020, registered in the SARSTerPED multicenter database. Most of the infants were registered in October and November 2020. 44% of the group were girls, and 56% were boys. At diagnosis, the most common symptoms were fever in 77% of the children, cough in 40%, catarrh in 37%. Pneumonia associated with COVID-19 was diagnosed in 23% of the children, and gastrointestinal symptoms in 31.3%. In 52% of the infants, elevated levels of D-dimers were observed, and in 40%, elevated levels of IL-6 serum concentration were observed. During the second wave of the pandemic, 6 times more infants were hospitalized, and the children were statistically significantly younger compared to the patients during the first wave (3 months vs 8 months, p < 0.0001 respectively). During the second wave, the infants were hospitalized for longer. COVID-19 in infants usually manifests as a mild gastrointestinal or respiratory infection, but pneumonia is also observed with falls in oxygen saturation, requiring oxygen therapy. Gastrointestinal symptoms are common in infants infected with SARS-CoV-2, and infant appetite disorders may lead to hospitalization. The clinical course of the disease differed significantly between the first and second wave of the pandemic. It seems that infants may play a role in the transmission of SARS-COV-2 infections in households, despite mild or asymptomatic courses; eating disorders in infants should be an indication for COVID-19 testing.

Pneumonia, gastrointestinal symptoms, comorbidities, and coinfections as factors related to a lengthier hospital stay in children with COVID-19-analysis of a paediatric part of Polish register SARSTer.

BACKGROUND: Although COVID-19 is associated with a mild course in children, a certain proportion requires admission to hospital due to SARS-CoV-2 infection and coexisting diseases. The prospective multicenter study aimed to analyze clinical factors influencing the length of the hospital stay (LoHS) in children with COVID-19. METHODS: The study included 1283 children from 14 paediatric infectious diseases departments with diagnosed SARS-CoV-2 infection. Children were assessed in respective centres regarding indications for admission to hospital and clinical condition. History data, clinical findings, laboratory parameters, treatment, and outcome, were collected in the paediatric SARSTer register. The group of children with a hospital stays longer than seven days was compared to the remaining patients. Parameters with a statistically significant difference were included in further logistic regression analysis. RESULTS: One thousand one hundred and ten children were admitted to the hospital, 763 children were hospitalized >24 h and 173 children >7 days. 268 children had comorbidities. Two hundred and eleven children had an additional diagnosis with coinfections present in 135 children (11%). Factors increasing the risk of higher LoHS included pneumonia [odds ratio-OR 3.028; 95% confidence interval-CI (1.878-4.884)], gastrointestinal symptoms [OR = 1.556; 95%CI (1.049-2.322)], or rash [OR = 2.318; 95%CI (1.216-4.418)] in initial clinical findings. Comorbidities [OR = 2.433; 95%CI (1.662-3.563)], an additional diagnosis [OR = 2.594; 95%CI (1.679-4.007)] and the necessity of the empirical antibiotic treatment [OR = 2.834; 95%CI (2.834-6.713)] were further factors related to higher LoHS. CONCLUSIONS: The clinical course of COVID-19 was mild to moderate in most children. Factors increasing the risk of higher LoHS included pneumonia, gastrointestinal symptoms, comorbidities, an additional diagnosis, and the empirical antibiotic treatment.

Clinical and Epidemiological Characteristics of 1283 Pediatric Patients with Coronavirus Disease 2019 during the First and Second Waves of the Pandemic-Results of the Pediatric Part of a Multicenter Polish Register SARSTer.

This prospective multicenter cohort study aimed to analyze the epidemiological and clinical characteristics of coronavirus disease 2019 (COVID-19) in children. The study, based on the pediatric part of the Polish SARSTer register, included 1283 children (0 to 18 years) who were diagnosed with COVID-19 between 1 March 2020 and 31 December 2020. Household contact was reported in 56% of cases, more frequently in younger children. Fever was the most common symptom (46%). The youngest children (0-5 years) more frequently presented with fever, rhinitis and diarrhea. Teenagers more often complained of headache, sore throat, anosmia/ageusia and weakness. One fifth of patients were reported to be asymptomatic. Pneumonia was diagnosed in 12% of patients, more frequently in younger children. During the second wave patients were younger than during the first wave (median age 53 vs. 102 months, p < 0.0001) and required longer hospitalization (p < 0.0001). Significantly fewer asymptomatic patients were noted and pneumonia as well as gastrointestinal symptoms were more common. The epidemiological characteristics of pediatric patients and the clinical presentation of COVID-19 are age-related. Younger children were more frequently infected by close relatives, more often suffered from pneumonia and gastrointestinal symptoms and required hospitalization. Clinical courses differed significantly during the first two waves of the pandemic.

The first report evaluating the post-exposure rabies prophylaxis in children exposed to animals in the Lublin Province (Eastern Poland) in 2010-2016 - a retrospective study.

INTRODUCTION: Rabies continues to be one of the most important viral diseases and remains a significant threat to public health across the globe. The World Health Organization (WHO) has determined that most rabies cases occur in children. Dog bites on humans are a major public-health problem. Poland has not achieved rabies free status yet. Post-exposure prophylaxis (PEP) in humans can effectively prevent death after exposure to a potentially infected animal. THE AIM: The main objective of this study was to estimate the frequency of PEP among children exposed to animals, who had attended consultations at the Department of Infectious Diseases for Children in the Jan Bozy Hospital in Lublin. PATIENTS AND METHODS: We retrospectively analyzed the medical records from the period of 2010-2016 of all pediatric patients (0-17 years of age) who had been exposed to animals and attended consultations at the Department of Infectious Diseases for Children in the Jan Bozy Hospital in Lublin. RESULTS: During the studied period, 519 children who had been exposed to animals attended consultations, and a prophylactic procedure consisting of active immunization was applied to 32.8%. The male children accounted for 55.3%. The mean age was 9.2 years. The biggest group of children (406) had been exposed to dogs, 62 children to cats, and 15 to rats. Most children had upper-limbs injuries. During the studied period, i.e. 2010-2016, there were 1713 confirmed cases of rabid animals in Poland, and 60 cases were recorded in the Lublin Province. We did not observe any cases of rabies in our exposed and vaccinated patients. CONCLUSIONS: The number of rabid animals in the Lublin Province had decreased to low levels, but the expected decrease in the number of PEP's administered did not occur. Since all children were vaccinated in accordance with the recommendations, the possible reason for vaccination's being administered in the quantities greater than the number of rabid animals recorded in the Lublin Province are bites by animals unavailable for veterinary observations and also the lack of more frequent reports regarding the current epizootic situation of rabies. The use of rabies immunoglobulin (RIG) in children in the Lublin Province is at a very low level, i.e. at 0.58%. The yearly numbers of exposed pediatric patients were at similar levels, which indicates that education programs should be introduce to reduce the number of animal bites in children.

In Search of Factors Negatively Affecting Vaccine Immunity to Pertussis in Preschool Children Before the Administration of the First Booster.

INTRODUCTION: The top priority for active immunoprophylaxis of pertussis is the immunisation of infants as they can sometimes develop severe multiple-organ complications. OBJECTIVES: The aim of the work is the identification of factors negatively affecting vaccine immunity to pertussis in preschool children prior to the administration of the first booster. PATIENTS AND METHODS: The research was conducted on 352 children from 4.5 to 5.9 years of age who were hospitalised in the University Children's Hospital in Lublin (Poland) from 1 January 2012 to 31 December 2015. The children taking part in the study had been administered all the mandatory vaccines from their birth to the age of 2 or 2.5 years old according to the Polish Immunisation Program 2008⁻2009. The immunoenzymatic method ELISA (enzyme-linked immunosorbent assay) was applied to assess vaccine immunity to tetanus, diphtheria, pertussis, Haemophilus influenzae type b (Hib), poliomyelitis (IPV), mumps, rubella and measles. The level of vaccine antibodies to hepatitis type B was determined chemilumiscently. RESULTS: The protective antibody titre was not found in 41 (11.65%) children before the administration of the booster. To verify the collective impact of parameters analysed on antibody titre to pertussis, the Generalized Linear Model (GLZ) was used. Gender, type of vaccine, asthma, Hib and mumps antibody titres have been shown to be predictors of vaccine immunity to pertussis. CONCLUSIONS: Immunomodulation considered on the example of titre of IgG antibody to pertussis can serve as a useful model of the assessment of development of acquired immunity after mandatory vaccinations.

A randomized study of fever prophylaxis and the immunogenicity of routine pediatric vaccinations.

OBJECTIVE: Prophylactic antipyretic use during pediatric vaccination is common. This study assessed whether paracetamol or ibuprofen prophylaxis interfere with immune responses to the 13-valent pneumococcal conjugate vaccine (PCV13) given concomitantly with the combined DTaP/HBV/IPV/Hib vaccine. METHODS: Subjects received prophylactic paracetamol or ibuprofen at 0, 6-8, and 12-16 h after vaccination, or 6-8 and 12-16 h after vaccination at 2, 3, 4, and 12months of age. At 5 and 13months, immune responses were evaluated versus responses in controls who received no prophylaxis. RESULTS: After the infant series, paracetamol recipients had lower levels of circulating serotype-specific pneumococcal anticapsular immunoglobulin G than controls, reaching significance (P<0.0125) for 5 serotypes (serotypes 3, 4, 5, 6B, and 23F) when paracetamol was started at vaccination. Opsonophagocytic activity assay (OPA) results were similar between groups. Ibuprofen did not affect pneumococcal responses, but significantly (P<0.0125) reduced antibody responses to pertussis filamentous hemagglutinin and tetanus antigens after the infant series when started at vaccination. No differences were observed for any group after the toddler dose. CONCLUSIONS: Prophylactic antipyretics affect immune responses to vaccines; these effects vary depending on the vaccine, antipyretic agent, and time of administration. In infants, paracetamol may interfere with immune responses to pneumococcal antigens, and ibuprofen may reduce responses to pertussis and tetanus antigens. The use of antipyretics for fever prophylaxis during infant vaccination merits careful consideration. ClinicalTrials.gov identifier: NCT01392378https://clinicaltrials.gov/ct2/show/NCT01392378?term=NCT01392378&rank=1.

Phase 3 trial evaluating the immunogenicity, safety, and tolerability of manufacturing scale 13-valent pneumococcal conjugate vaccine.

13-valent pneumococcal conjugate vaccine (PCV13) includes polysaccharide conjugates from six pneumococcal serotypes in addition to those in the licensed 7-valent vaccine, thereby offering expanded protection against pneumococcal disease. The phase 3 trial reported here was conducted per a regulatory requirement to evaluate the immunogenicity, safety, and tolerability of two lots of the final PCV13 formulation that differed with respect to production scale but not the manufacturing process. The anti-pneumococcal polysaccharide immunogenicity and safety/tolerability were found to be similar between the two PCV13 vaccine lots.