Department of Maternal, Child Health and Urological Sciences, Sapienza University of Rome, Rome, Italy.
B Cell Unit, Immunology Research Area, Bambino Gesù Children's Hospital, Istituti di Ricovero e Cura a Carattere Scientifico (IRCCS), Rome, Italy.
Front Cell Infect Microbiol. 2024 Mar 27;14:1231697. doi: 10.3389/fcimb.2024.1231697. eCollection 2024.
The anti-COVID-19 intramuscular vaccination induces a strong systemic but a weak mucosal immune response in adults. Little is known about the mucosal immune response in children infected or vaccinated against SARS-CoV-2. We found that 28% of children had detectable salivary IgA against SARS-CoV-2 even before vaccination, suggesting that, in children, SARS-CoV-2 infection may be undiagnosed. After vaccination, only receptor-binding domain (RBD)-specific IgA1 significantly increased in the saliva. Conversely, infected children had significantly higher salivary RBD-IgA2 compared to IgA1, indicating that infection more than vaccination induces a specific mucosal immune response in children. Future efforts should focus on development of vaccine technologies that also activate mucosal immunity.
抗 COVID-19 肌肉内疫苗接种可在成年人中引起强烈的全身免疫反应，但粘膜免疫反应较弱。对于感染或接种 SARS-CoV-2 疫苗的儿童的粘膜免疫反应知之甚少。我们发现，即使在接种疫苗之前，仍有 28%的儿童的唾液中可检测到针对 SARS-CoV-2 的 IgA，这表明儿童中的 SARS-CoV-2 感染可能未被诊断。接种疫苗后，唾液中仅受体结合域（RBD）特异性 IgA1 显著增加。相反，感染 SARS-CoV-2 的儿童的唾液 RBD-IgA2 明显高于 IgA1，表明感染比接种疫苗更能诱导儿童的特异性粘膜免疫反应。未来的研究应集中于开发可同时激活粘膜免疫的疫苗技术。
