Immunogenicity of coronavirus disease 2019 vaccines in children: A review with ChatGPT

Abstract

<p>SARS-CoV-2 causes millions of infection cases and coronavirus disease 2019 (COVID-19)-related deaths worldwide. In addition to acute illnesses, children and adolescents suffer from post-infectious complications. Vaccination is a promising preventative treatment that can confer protection from these devastating outcomes. Utilizing ChatGPT, this review discusses the immunogenicity of mRNA and inactivated COVID-19 vaccines in children and adolescents. Rapid vaccine discovery during the COVID-19 pandemic led to the approval of the mRNA vaccines that stimulate potent antibody responses in pediatric population, and the younger age groups develop higher neutralizing and non-neutralizing antibody responses than those who are older. Natural infection induces weaker antibody responses than vaccination. Vaccine-induced humoral immunity decreases over time, as antibodies decline six months after the second dose. However, antibody avidity increases, which partly maintains neutralization and Fc-effector functions that provide more durable protection. Inactivated COVID-19 vaccines generate strong antibody responses in children and adolescents. They induce T cell responses against multiple structural protein antigens, although their neutralizing antibody responses appear weaker and wane more quickly than mRNA vaccines. Full-dose intradermal administration and heterologous prime-boost may improve the immunogenicity of inactivated vaccines. In children and adolescents, immune protection from the pre-Omicron variants of concern (VOCs) is maintained. Vaccination induces less antibody neutralization against the Omicron variant, but non-neutralizing antibodies and T cell responses persist. Hybrid immunity provides stronger immunogenicity against SARS-CoV-2 in the pediatric population. Future research must focus on long-term immunity, interaction with breakthrough reinfections, cross-reactivity against new VOCs, T cell immunogenicity and immunogenicity in young children.</p>