Antibody Persistence After Primary SARS-CoV-2 Infection and Protection Against Future Variants Including Omicron in Adolescents: National, Prospective Cohort Study

Abstract

Background: Antibodies are a measure of immunity after primary infection, which may help protect against further SARS-CoV-2 infections. They may also provide some cross-protection against SARS-CoV-2 variants. There are limited data on antibody persistence and, especially, cross-reactivity against different SARS-CoV-2 variants after primary infection in children. Methods: We initiated enhanced surveillance in 18 secondary schools to monitor SARS-CoV-2 infection and transmission in September 2020. Students and Staff provided longitudinal blood samples to test for variant-specific SARS-CoV-2 antibodies using in-house receptor binding domain assays. We recruited 1189 students and 1020 staff; 160 (97 students, 63 staff) were SARS-CoV-2 nucleocapsid-antibody positive at baseline and had sufficient serum for further analysis. Results: Most participants developed sustained antibodies against their infecting [wild-type (WT)] strain as well as cross-reactive antibodies against the Alpha, Beta and Delta variants but at lower titers than WT. Staff had significantly lower antibodies titers against WT as cross-reactive antibodies against the Alpha, Beta and Delta variants than students (all P < 0.01). In participants with sufficient sera, only 2.3% (1/43) students and 17.2% (5/29) staff had cross-reactive antibodies against the Omicron variant; they also had higher antibody titers against WT (3042.5; 95% confidence interval: 769.0–12,036.2) than those who did not have cross-reactive antibodies against the Omicron variant (680.7; 534.2–867.4). Conclusions: We found very high rates of antibody persistence after primary infection with WT in students and staff. Infection with WT induced cross-reactive antibodies against Alpha, Beta and Delta variants, but not Omicron. Primary infection with WT may not be cross-protective against the Omicron variant.

Single intranasal immunization with attenuated Wuhan-like SARS-CoV-2 provides highly effective cross-protection against Delta and Omicron variants of concern

“…Для гетерологичных штаммов, относящихся к вариантам Delta и Omicron, нейтрализующая активность была предсказуемо ниже или отсутствовала (рис. 2, б), что определяется изменениями антигенных свойств S-белка вируса в ходе эволюции и согласуется с результатами предыдущих исследований [2,3,15,23,24].…”

“…Лицензированные вакцины (инактивированные, векторные, рекомбинантные и мРНК-вакцины) преимущественно основаны на S-белке SARS-CoV-2 и стимулируют как гуморальный, так и клеточный иммунитет [37][38][39]; однако в большей степени их эффективность определяется индукцией нейтрализующих антител. Изменчивость S-белка и появление новых эпидемиологически значимых вариантов вируса (VOC) приводит к «ускользанию» вируса из-под иммунологического надзора и снижению эффективности таких вакцин [2,3,23,24,40]. Более того, продолжающаяся эволюция варианта Omicron привела к появлению таких его сублиний, которые «ускользают» от адаптивного иммунитета, индуцированного даже предыдущим заражением вирусами родительских сублиний Omicron.…”

Single intranasal immunization with attenuated Wuhan-like SARS-CoV-2 provides highly effective cross-protection against Delta and Omicron VOCs

“…For the heterologous variants of the virus, Delta and especially Omicron, the neutralizing activity was predictably lower or absent, which is consistent with changes in the antigenic properties of the virus S-protein in the course of evolution and the results of previous studies (рис. 2В) (Aiano et al, 2023;Bowen et al, 2022;Dejnirattisai et al, 2022;Faizuloev et al, 2023;Wang et al, 2022).…”

“…However, the post-vaccine protection against infection and symptomatic infection with the Omicron variant composed only 40-50% for mRNA vaccines (declared as the most effective vaccines) in the rst 3 months p.i., and declines rapidly to 10-20% thereafter(Amir et al, 2023;Lau et al, 2023;Menegale et al, 2023;Paul et al, 2023). Booster immunization can restore this value to baseline, but the duration of surveillance and a decrease in the effectiveness of such vaccines(Aiano et al, 2023; Bowen et al, 2022;Dejnirattisai et al, 2022;Seidel et al, 2023;Wang et al, 2022). The ongoing evolution of the Omicron variant has led to the emergence of such of its sublineages that escape adaptive immunity induced even by previous infection with parental Omicron sublineages.…”