PDF(Pubmed)
Abstract：
BACKGROUND: There are few reports of longitudinal serologic responses in children following Sars-CoV-2 infection and vaccination. This study describes longitudinal SARS-CoV-2 antibody responses following infection, vaccination, or both (hybrid immunity) in a cohort of Canadian children. The objectives of our study were to compare antibody levels following SARS-CoV-2 infection, vaccination, and hybrid immunity and to examine antibody decline after final antigen exposure.
METHODS: The Alberta Childhood COVID-19 Cohort (AB3C) study was a prospective longitudinal cohort study conducted from July 2020 to September 2022 with repeat sampling across 5 visits. Children under 18 years of age were enrolled for serial measurement of antibody responses to SARS-CoV-2 virus vaccine and infection.
RESULTS: The final sample size was 919; participants were 50.5% female, 48.2% were > 12 years and 88.5% were white ethnicity. The median peak spike IgG level of those with only infection was not different from those with no vaccination or infection (233 AU/mL (IQR: 99-944 AU/mL) vs. 3 AU/mL (IQR: 1-5 AU/mL; P = 0.1765). Participants with infections after vaccination had higher IgG levels than those where infection preceded vaccination (median: 36,660 (IQR: 22,084 - 40,000 AU/mL) vs. 17,461 AU/mL (IQR: 10,617 - 33,212 AU/mL); P < 0.0001). In a linear mixed methods model, children with infection-only had low levels of antibody that stayed stable over the study duration without further antigen exposures. Those with infection after vaccination had the slowest rate of antibody decline over time at 4% (95%CI: 2-5%) per week, compared with children where infection preceded vaccine 7% (95%CI: 6-8%) per week.
CONCLUSIONS: Children with hybrid immunity conferred through vaccination (2 + doses) followed by a SARS-CoV-2 infection had the highest and longest lasting antibody levels, compared to children who had an infection followed by vaccination, vaccination-only, or infection-only. The longer-term clinical importance of these findings, related to prevention of repeated infections and severe outcomes and need for further vaccine doses, is not yet known.
METHODS: The Alberta Childhood COVID-19 Cohort (AB3C) study was a prospective longitudinal cohort study conducted from July 2020 to September 2022 with repeat sampling across 5 visits. Children under 18 years of age were enrolled for serial measurement of antibody responses to SARS-CoV-2 virus vaccine and infection.
RESULTS: The final sample size was 919; participants were 50.5% female, 48.2% were > 12 years and 88.5% were white ethnicity. The median peak spike IgG level of those with only infection was not different from those with no vaccination or infection (233 AU/mL (IQR: 99-944 AU/mL) vs. 3 AU/mL (IQR: 1-5 AU/mL; P = 0.1765). Participants with infections after vaccination had higher IgG levels than those where infection preceded vaccination (median: 36,660 (IQR: 22,084 - 40,000 AU/mL) vs. 17,461 AU/mL (IQR: 10,617 - 33,212 AU/mL); P < 0.0001). In a linear mixed methods model, children with infection-only had low levels of antibody that stayed stable over the study duration without further antigen exposures. Those with infection after vaccination had the slowest rate of antibody decline over time at 4% (95%CI: 2-5%) per week, compared with children where infection preceded vaccine 7% (95%CI: 6-8%) per week.
CONCLUSIONS: Children with hybrid immunity conferred through vaccination (2 + doses) followed by a SARS-CoV-2 infection had the highest and longest lasting antibody levels, compared to children who had an infection followed by vaccination, vaccination-only, or infection-only. The longer-term clinical importance of these findings, related to prevention of repeated infections and severe outcomes and need for further vaccine doses, is not yet known.
摘要：
背景：关于儿童在Sars-CoV-2感染和接种疫苗后出现纵向血清学反应的报道很少。这项研究描述了感染后的纵向SARS-CoV-2抗体反应，疫苗接种,或两者（混合免疫）在加拿大儿童队列。我们研究的目的是比较SARS-CoV-2感染后的抗体水平，疫苗接种,和混合免疫，并检查最终抗原暴露后抗体的下降。
方法：艾伯塔省儿童COVID-19队列（AB3C）研究是一项前瞻性纵向队列研究，于2020年7月至2022年9月进行，在5次访问中重复采样。18岁以下的儿童参加了对SARS-CoV-2病毒疫苗和感染的抗体反应的连续测量。
结果：最终样本量为919；参与者为50.5%女性，>12岁的占48.2%，白人占88.5%。仅感染的患者的峰值IgG水平中位数与未接种疫苗或未感染的患者没有差异（233AU/mL（IQR：99-944AU/mL）与3AU/mL(IQR:1-5AU/mL;P=0.1765)。接种疫苗后感染的参与者的IgG水平高于接种疫苗前感染的参与者（中位数：36,660（IQR：22,084-40,000AU/mL）与17,461AU/mL（IQR：10,617-33,212AU/mL）；P<0.0001）。在线性混合方法模型中，仅感染儿童的抗体水平较低,在没有进一步抗原暴露的情况下,在研究期间保持稳定.接种疫苗后感染的人随着时间的推移抗体下降率最慢，为每周4％（95CI：2-5％），与感染前每周接种疫苗7%(95CI:6-8%)的儿童相比。
结论：通过疫苗接种（2剂量）和SARS-CoV-2感染赋予混合免疫的儿童具有最高和最长的持续抗体水平，与感染后接种疫苗的儿童相比，仅接种疫苗，或仅感染。这些发现的长期临床重要性，与预防反复感染和严重结局以及需要更多疫苗剂量有关，还不知道。
方法：艾伯塔省儿童COVID-19队列（AB3C）研究是一项前瞻性纵向队列研究，于2020年7月至2022年9月进行，在5次访问中重复采样。18岁以下的儿童参加了对SARS-CoV-2病毒疫苗和感染的抗体反应的连续测量。
结果：最终样本量为919；参与者为50.5%女性，>12岁的占48.2%，白人占88.5%。仅感染的患者的峰值IgG水平中位数与未接种疫苗或未感染的患者没有差异（233AU/mL（IQR：99-944AU/mL）与3AU/mL(IQR:1-5AU/mL;P=0.1765)。接种疫苗后感染的参与者的IgG水平高于接种疫苗前感染的参与者（中位数：36,660（IQR：22,084-40,000AU/mL）与17,461AU/mL（IQR：10,617-33,212AU/mL）；P<0.0001）。在线性混合方法模型中，仅感染儿童的抗体水平较低,在没有进一步抗原暴露的情况下,在研究期间保持稳定.接种疫苗后感染的人随着时间的推移抗体下降率最慢，为每周4％（95CI：2-5％），与感染前每周接种疫苗7%(95CI:6-8%)的儿童相比。
结论：通过疫苗接种（2剂量）和SARS-CoV-2感染赋予混合免疫的儿童具有最高和最长的持续抗体水平，与感染后接种疫苗的儿童相比，仅接种疫苗，或仅感染。这些发现的长期临床重要性，与预防反复感染和严重结局以及需要更多疫苗剂量有关，还不知道。
