Study required on susceptibility of children to Corona variants: WHO
Geneva: With schools reopening at many places, the use of public health and social measures (PHSM), including physical distancing, cleaning hands, coughing into a bent elbow or a tissue, adequate ventilation in indoor settings, and masks, should be consistently and appropriately implemented for all ages in schools, especially since children under the age of 12 years are generally not yet eligible for vaccination, the World Health Organization has cautioned.
Outbreaks of COVID-19 have been identified in secondary schools, summer camps and day, particularly when neither physical distancing nor masks were used to reduce risk. There is some preliminary evidence that children may be less infectious, than adolescents and adults, as measured by secondary attack rates.
Children and adolescents who become infected with SARS-CoV-2 shed the virus in their respiratory tract and may also shed virus in their faeces. Among individuals who were positive for SARS-CoV-2 who were tested at the same time point after symptom onset, SARS-CoV-2 viral RNA shedding in the respiratory track appeared similar in children, adolescents and adults.
The relationship between age, viral load and transmission across the full symptom spectrum of SARS-CoV2 infection has not been comprehensively investigated because people with no, or mild, symptoms are seldom tested systematically, the WHO stated today.
Thus, it said, the relative transmissibility of SARS-CoV2 at different ages remains uncertain, largely due to the challenges involved in disentangling the influences of biological, host, virus and environmental factor.
Younger children (under five years old, older children and adolescents (10 to 19 years old) usually have fewer and milder symptoms of SARS-CoV2 infection than adults >25 years old and are less likely than adults to experience severe COVID-19.
Milder symptoms and asymptomatic presentation often mean less frequent care seeking for these groups; thus, children and adolescents tend to be tested less frequently and cases may go unreported. Early reports suggested an age-dependent risk of severe disease with those under one year experiencing more severe disease, although several reviews show that neonates (first 28 days of life) have mild disease as compared to other paediatric patients.
WHO warned that the frequency and characteristics of prolonged clinical symptoms (known as post COVID-19 condition, or post-acute sequelae of SARS-CoV-2 infection) in children and adolescents are still under investigation.
Moreover, a hyper-inflammatory syndrome, referred to as paediatric inflammatory multisystem syndrome,temporally associated with SARS-CoV-2 (PIMS-TS) in Europe and multisystem inflammatory syndrome in children (MIS-C) in the United States of America, although rare, can occur, and complicates recovery from COVID-19.
The severity of disease in children and adolescents caused by SAR-CoV-2 variants of concern(VOC), in comparison with non-VOC lineages, remains under investigation, it stated.
The risk of transmission to and from children and adolescents depends on contextual factors such as the level of community transmission and the measures implemented to control the virus, host factors in the child, as well as biological factors related to the virus itself. However, children and adolescents of all ages become infected and also transmit SARS-CoV-2 to others.
When infected with SARS-CoV-2, these children and adolescents generally present with milder symptoms of COVID-19 disease; although infection with the variants of SARS CoV-2, including the Delta variant, require more investigation to determine if this will remain the case.
WHO stated that younger children may be less susceptible than older children and adolescents, but the precise role of children and adolescents in the overall transmission of SARS-CoV-2 still requires further investigation.It further noted that children under the age of one year and within the neonatal period (first 28 days after birth) have a higher risk of diseases which have overlapping presentation with COVID-19, such as pneumonia and malaria.
Additionally, age disaggregation has not been systematically provided in the current literature and the results of these studies are context-specific such as timing within the pandemic and an emphasis on hospitalized patients.
The risk of becoming infected with SARS-CoV-2 depends on a combination of susceptibility (host biological factors), biological properties of the virus, environmental factors associated with exposure type (going to work, or school etc.) and exposure intensity (level of community transmission and adherence to public health and social measures (PHSM)).
Multiple population-based SARS-CoV-2 sero-prevalence and viral shedding studies have investigated whether children and adolescents are infected at the same rate as adults, but the results have been mixed, possibly because of the studies being conducted at different time points in the pandemic when populations were subjected to different levels of PHSM20. Even so, we do know that children of all ages can become infected and can spread the virus to others.
Data on the global incidence of COVID-19 in adolescents suggests they test positive for SARS-CoV-2 at a higher proportion than children, however, sero-prevalence surveys are needed to provide more information.
Additionally, more detailed epidemiological information about the factors influencing susceptibility of children and adolescents to the new SARS-CoV-2 variants is urgently needed, it stated.
– global bihari bureau