Children and COVID-19 Research Library

This report compiles the good practices and lessons learned from countries implementing real-time monitoring (RTM) - activities that employ digital technologies to accelerate the sharing, analysis and use of data to improve campaign quality - for immunization campaigns. Data and information were collected using a mix of interviews (United Nations Children's Fund, World Health Organization, and regional and country office staff); consultations with key partners; a field mission to Pakistan; and documents and journal articles. Four countries with robust experience implementing RTM technologies for immunization campaigns - Indonesia, Pakistan, Uganda and Zambia - were included as case studies.

While COVID-19 continues to spread across the globe, diligent efforts are made to understand its attributes and dynamics to help develop treatment and prevention measures. The paradox pertaining to children being the least affected by severe illness poses exciting opportunities to investigate potential protective factors. The Hypothesis of  this paper is that childhood vaccination against pertussis (whooping cough) might play a non-specific protective role against COVID-19 through heterologous adaptive responses in this young population. Pertussis is a vaccine-preventable infectious disease of the respiratory tract and it shares many similarities with COVID-19 including transmission and clinical features. Although pertussis is caused by a bacterium (Bordetella pertussis) while COVID-19 is a viral infection (SARS-CoV-2), previous data showed that cross-reactivity and heterologous adaptive responses can be seen with unrelated agents of highly divergent groups, such as between bacteria and viruses.

Compared to adults, children with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have predominantly mild or asymptomatic infections, but the underlying immunological differences remain unclear. This study describes clinical features, virology, longitudinal cellular, and cytokine immune profile, SARS-CoV-2-specific serology and salivary antibody responses in a family of two parents with PCR-confirmed symptomatic SARS-CoV-2 infection and their three children, who tested repeatedly SARS-CoV-2 PCR negative. Cellular immune profiles and cytokine responses of all children are similar to their parents at all timepoints. All family members have salivary anti-SARS-CoV-2 antibodies detected, predominantly IgA, that coincide with symptom resolution in 3 of 4 symptomatic members. Plasma from both parents and one child have IgG antibody against the S1 protein and virus-neutralizing activity detected. Using a systems serology approach, this study shows higher levels of SARS-CoV-2-specific antibody features of these family members compared to healthy controls. These data indicate that children can mount an immune response to SARS-CoV-2 without virological confirmation of infection, raising the possibility that immunity in children can prevent the establishment of SARS-CoV-2 infection. 

The COVID-19 pandemic has evolved into arguably the largest global public health crisis in recent history—especially in the absence of a safe and effective vaccine or an effective anti-viral treatment. As reported, the virus seems to less commonly infect children and causing less severe symptoms among infected children. This narrative review provides an inclusive view of scientific hypotheses, logical derivation, and early analyses that substantiate or refute such conjectures. At the completion of a relatively less restrictive search of this evolving topic, 13 articles—all published in 2020, were included in this early narrative review.

As with other types of coronaviruses, SARS-CoV-2 affects children less frequently, and it has been observed that the disease is mild. In the pathogenesis of a standard viral infection, the pathogen’s contact with the mucosa is initially followed by an innate immunity response. T cells are the primary decisive element in adaptive immunity capability. For this reason, the adaptive immune response mediated by the thymus is a process that regulates the immune response responsible for preventing invasive damage from a virus. Regulatory T cells (T-reg) are active during the early periods of life and have precise roles in immunomodulation. The thymus is highly active in the intrauterine and neonatal period; it begins to shrink after birth and continues its activity until adolescence. The loss of T-reg function by age results in difficulty with the control of the immune response, increased inflammation as shown in coronavirus disease (COVID-19) as an inflammatory storm. Also, the thymus is typically able to replace the T cells destroyed by apoptosis caused by the virus. Thymus and T cells are the key factors of pathogenesis of SARS-CoV-2 in children. Since thymus activity and T lymphocyte function in children protect them against the virus effects, stimulating and preventing the inhibition of the thymus can be possible treatment components against COVID-19.

This paper reports the descriptive experience of 14 cases of acro-ischemia in children and adolescents observed in the territorial area of Ravenna and Rimini. The cases were subjected to the nasopharyngeal swab and to the search for antibodies with ELISA method for CoViD-19 both with negative results.

Coronavirus-related service disruptions threaten to reverse the decade-long progress made for children and pregnant women in the fight against HIV.

The incidence of COVID-19 in children and teenagers is only about 2% in China. Children had mild symptoms and hardly infected other children or adults. It is worth considering that children are the most vulnerable to respiratory pathogens, but fatal SARS-like virus had not caused severe cases among them. According to the pathological studies of COVID-19 and SARS, a sharp decrease in T lymphocytes leads to the breakdown of the immune system. The cellular immune system of children differs from that of adults may be the keystone of atypical clinical manifestations or even covert infection. The frequent childhood vaccinations and repeated pathogens infections might be resulting in trained immunity of innate immune cells, immune fitness of adaptive immune cells or cross-protection of antibodies in the children. Therefore, due to lack of specific vaccine, some vaccines for tuberculosis, influenza and pneumonia may have certain application potential for the front-line health workers in the prevention and control of COVID-19. However, for high-risk susceptible populations, such as the elderly with basic diseases such as hypertension and diabetes, it is necessary to explore the remedial effect of the planned immune process on their immunity to achieve the trained immunity or immune fitness, so as to improve their own antiviral ability.

Children, because of having an immature immune system, are usually more prone than the adults to the mi-crobial infections and have more severe symptoms, which is especially true for the newborns, and very young children. However, the review of clinical data from the current COVID-19 pandemic indicates otherwise. This article explains what are the main features and components of children's immune system, the role of maternal transmission of immunity, and what are the possible explanations for the seemingly lower infection rate and severity of COVI-19 in children.