Children’s SARS-CoV-2

Incidence of children

Through a pandemic, children account for the lowest percentage of reported COVID-19 cases [1].. In the early stages of the pandemic, the pediatric case notification rate was the lowest, but subsequent studies confirmed the case because of the high incidence and low testing rate of asymptomatic and mild cases in children. It has been suggested that the results may be low. Decreased sensitivity (see Sensitivity) [2].. As the coverage of adult vaccination has expanded, children have become a relatively large proportion of reported cases.The spread of more contagious mutants with improved antigenic escape capacity resulted in higher transmission in all age groups, including children, resulting in an increased 14-day case notification rate. [1,3]..

Through various waves of the pandemic, differences in 14-day case notification rates were observed between child age groups, with the lowest rate among children being widely observed in the youngest age group and higher adolescent age. Higher rates have been observed in the group.Sometimes reflects or exceeds that of young adults [1,4].. These differences may be the result of differences related to test rates, clinical symptoms, vaccination rates, social mix, and age groups of biological susceptibility.

See below for more information on case notification rates.

Sensitivity

Due to the relatively small number of cases of SARS-CoV-2 infection reported in children throughout the pandemic, it was hypothesized that children may be less susceptible than adults.[5]..However, the conclusions of published studies are inconsistent: reduced notification in children, lower case confirmation (due to mild and asymptomatic cases), reduced biological susceptibility, reduced social mixing. May be the result of a combination of factors such as [2]..

Severity

Children often experience mild or asymptomatic COVID-19 [6]..The risk of developing serious illnesses that lead to hospitalization and death is lower than in adults [7].. Approximately 117 hospitalizations for every 10,000 reported symptomatic pediatric cases during the two months of one study from 10 EU countries (August 3, 2020 to October 3, 2021) (8 of which) The case required ICU admission and respiratory assistance). [8]..

Although the majority of children hospitalized with COVID-19 do not have comorbidities, comorbidities also increase the risk of serious illness, hospitalization, and death in children. [8].. As the coverage of adult vaccination expanded (and thus the rate of adult hospitalization declined), children increased the rate of hospitalization, and so did child hospitalization during periods of high infection rates.However, the hospitalization rate for SARS-CoV-2 cases notified among children remains low. [9]..

The lower proportion of severe COVID-19 in children compared to adults is in contrast to infections caused by many other respiratory viruses in which severe illness is more commonly observed in children. A combination of various factors reduces protection in adults (ACE2 receptor expression, decreased immune function with age, increased prevalence of comorbidity associated with severe COVID-19, etc.) in children. Increased protection (reduced social mix, differences, etc.) may occur. Immunity) [10]..In addition, evidence also shows that vaccination effectively reduces the severity of COVID-19 disease between adults and children. [4,11]..

The impact and prevalence of post-COVID-19 status (“long COVID”) in EU children is unclear due to the lack of quality pan-European studies and a clear case definition. [12]..Several studies report the post-COVID-19 status of children [12,13].. Children who experience severe COVID-19 are more likely to experience long-term symptoms and may be at increased risk in children over the age of 10 and children with certain underlying illnesses. [13,14].. Denmark in 37522 children aged 0-17 years with SARS-CoV-2 infection confirmed by RT-PCR (and a control group of 78037 children with no history of SARS-CoV-2 infection) In a large national cohort study of, the most common long-term symptoms in school children with a history of SARS-CoV-2 infection are odor loss, taste loss, malaise, respiratory problems, dizziness, and muscle weakness. I had a chest pain. [15]..

Inflammatory polyphyletic syndrome known as pediatric inflammatory polyphyletic syndrome temporarily associated with SARS-CoV-2 (PIMS-TS) [16] Or Pediatric Multisystem Inflammatory Syndrome (MIS-C) [17]A rare and serious result of COVID-19 in children [13].. PIMS-TS / MIS-C shares common clinical features with other pediatric inflammatory syndromes such as Kawasaki disease, toxic shock syndrome, and macrophage activation syndrome. Pediatrics with PIMS-TS / MIS-C often develop 4 to 6 weeks after infection, including Kawasaki disease-like symptoms, life-threatening shock, persistent fever, inflammation, and mild gastrointestinal illness. , Shows a wide range of clinical symptoms.Symptoms [1].. Median age for PIMS-TS / MIS-C cases is 8 years [18,19].. This condition generally occurs in children who are previously healthy and often experience a mild or asymptomatic early SARS-CoV-2 infection. [13,19].. Most children with serious illness due to PIMS-TS / MIS-C show good results and recover with intensive care support and appropriate treatment. [1]..

Uncertainty remains regarding the post-COVID-19 status and the effects of highly infectious variants such as the Variant of Concern Omicron Mutant (VOC) on MIS-C. [3]And the severity of COVID-19 infection in children.

For more information on the post-COVID-19 status and PIMS-TS, see ECDC Clinical features Latest evidence page..

School considerations

Children can become infected with SARS-CoV-2, but it is generally concluded that school infections do not promote infection in the community, but follow it. .. [20-23].. There is limited evidence of the effectiveness of school closures in reducing communication. Because these were often implemented at the same time as wide social restrictions. [24].. There is some evidence that the closure of secondary schools has a greater impact on reducing community infections than elementary schools. This is consistent with the infection rates observed in older and younger age groups of children. [1].. Although fragmented evidence of the impact of individual infection control measures is lacking, schools are able to increase community infection rates by implementing multi-layered mitigation strategies at schools, including reduced contact, non-pharmaceutical interventions, and surveillance. You can stay open even in high conditions. [25,26]However, further observational and studies are needed.

ECDC technical report on the role of the school environment in children’s COVID-19 and communication.

vaccination

Vaccination is recommended for all EU / EEA countries aged 12 to 17 years, and some countries currently recommend booster immunization for this age group. [4].. The European Medicines Agency (EMA) has approved vaccination for 6-11 years old (Spikevax, Cominarty).

Vaccine efficacy data available for adolescents from the period when Delta was the predominant variant shows a very high level of protection against infection, symptomatic disease, and severe disease. [4]..Adult vaccine protection against serious diseases caused by Omicron VOC is also strong, but so far it has been concluded that current vaccines are less effective in preventing infections, and vaccination of children is not possible. Population generally suggests no effect on reducing infections [27]..

Due to the circulation of variants such as Omicron and the low risk of serious outcomes of COVID-19 in children without comorbidities, the direct benefit of vaccination in children may therefore be lower than in adults. I have. [28]..However, vaccination is still beneficial for children at high risk of severe illness and can be protected from post-COVID-19 conditions and PIMS-TS / MIS-C. [4]..

See below for the latest data on COVID-19 vaccination in children and adolescents in the EU / EEA.

ECCC Technical Report on COVID-19 Vaccination in Children:

Information on the safety of the COVID-19 vaccine:

Conclusion

For children, the risk of SARS-CoV-2 infection and serious illness is low. However, children with comorbidity are at increased risk of serious illness. Vaccination is especially important for children at high risk of severe illness. In order to ensure the safe operation of schools and limit the transmission of children, it is important to implement multi-layered mitigation measures at schools, especially during periods of high community transmission.

Most of the data currently available in peer-reviewed studies and systematic reviews are pre-distributed Delta and Omicron VOCs, limiting the certainty of conclusions that can be drawn.