Children's SARS-CoV-2 Infection and Their Vaccination

Abstract

SARS-CoV-2, a novel coronavirus, causes respiratory tract infections and other complications in affected individuals, and has resulted in numerous deaths worldwide. The unprecedented pace of its transmission worldwide, and the resultant heavy burden on healthcare systems everywhere, prompted efforts to have effective therapeutic strategies and vaccination candidates available to the global population. While aged and immunocompromised individuals form a high-risk group for COVID-19 and have severe disease outcome, the rate of infections among children has also increased with the emergence of the Omicron variant. In addition, recent reports of threatening SARS-CoV-2-associated complications in children have brought to the forefront an urgent necessity for vaccination. In this article, we discuss the current scenario of SARS-CoV-2 infections in children with a special focus on the differences in their immune system response as compared to adults. Further, we describe the various available COVID-19 vaccines, including the recent bivalent vaccines for children, in detail, intending to increase willingness for their acceptance.

Keywords: EUA; MIS-C; Omicron; SARS-CoV-2.

Figure 1

Levels of maternal IgG antibody transferred from mother to infant wanes during 0–6 months after birth. Maternal anti-SARS-CoV-2 IgG antibodies acquired either by natural infection or vaccination are transferred to the fetus via placenta. The level of maternal antibodies decreases with the infant’s age and lasts up to 6 months. SARS-CoV-2 infection or COVID-19 vaccination during 20–32 weeks of gestation generated the highest antibody titer in pregnant women. This gradually declines when tested in umbilical cord samples at the time of birth, and then further declines at 2 months after birth as observed in infant serum samples and reaches a minimal amount at the age of 6 months, as represented in Figure 1.

Figure 2

Organs affected in MIS-C immunopathological disorder in children. This disorder affects multiple organs and shows a systemic immune response. It mainly causes respiratory distress, cardiac comorbidities, gastrointestinal upset, and vascular dysfunction. This disorder is associated with demographic features such as various age form, ethnicity, and obesity level.