COVID-19 Infection in Children and Infants: Current Status on Therapies and Vaccines

Abstract

Since the beginning in December 2019, the SARS-CoV-2 outbreak appeared to affect mostly the adult population, sparing the vast majority of children who only showed mild symptoms. The purpose of this investigation is to assess the status on the mechanisms that give children and infants this variation in epidemiology compared to the adult population and its impact on therapies and vaccines that are aimed towards them. A literature review, including in vitro studies, reviews, published guidelines and clinical trials was performed. Clinical trials concerned topics that allowed a descriptive synthesis to be produced. Four underlying mechanisms were found that may play a key role in providing COVID-19 protection in babies. No guidelines are available yet for therapy due to insufficient data; support therapy remains the most used. Only two vaccines are approved by the World Health Organization to be used in children from 12 years of age, and there are currently no efficacy or safety data for children below the age of 12 years. The COVID-19 clinical frame infection is milder in children and adolescents. This section of the population can act as vectors and reservoirs and play a key role in the transmission of the infection; therefore, vaccines are paramount. More evidence is required to guide safely the vaccination campaign.

Keywords: COVID-19; Pfizer; SARS-CoV-1; SARS-CoV-2; antibodies; children; dentistry; pregnancy; therapy; vaccines.

Figure 1

Rate of infection in the pediatric population after 4 May 2020.

Figure 2

Schematic representation of telomeres as a key factor in sustaining MSCs and progenitor stem cell proliferation, thus leading to their anti-inflammatory effect by blocking the production of pro-inflammatory cytokines (IL-6, TNF-α, IFN-γ). [interleukine: IL; tumor necrosis factor-α: TNF-α; Interferon gamma: IFN-γ; graft versus host disease: GVHD].

Figure 3

Moderna vaccine general characteristics, storage properties, administration dosages and variants’ efficacy. High: the receptors key-to-enter interaction mechanisms between the viral vector and the human host cell membrane. Low: the lipid-based nanoparticle with the mRNA is able to enter through a cellular endosome into the human cell. Inside the cell, the ionizable lipidic component of the endosome membrane is able to become charged positively producing a release of the lipid-based nanoparticle and mRNA into the cytoplasm. Then the ribosomes is able to synthetize proteins and messengers from mRNA producing an increase of the antibodies’ expression and an activation of the T cells’ response.

Figure 4

Pfizer/BioNTech vaccine general characteristics, storage properties, administration dosages and variants’ efficacy. High: the receptors key-to-enter interaction mechanisms between the viral vector and the human host cell membrane Lower: the lipid-based nanoparticle with the mRNA is able to enter through a cellular endosome into the human cell. Inside the cell, the ionizable lipidic component of the endosome membrane is able to become charged positively producing a release of the lipid-based nanoparticle and mRNA into the cytoplasm. Then the ribosomes is able to synthetize proteins and messengers from mRNA producing an increase of the antibodies’ expression and an activation of the T cells’ response.