背景:由于当前的疫苗接种或自然感染引起的预先存在的抗体对新出现的SARS-CoV-2变体的保护作用减弱是全球关注的问题。这是否是因为对SARS-COV-2的免疫力下降尚不清楚。
目的:我们旨在研究接种疫苗的初始(VN)和自然感染(NI)个体中抗体同种型反应的动力学。
方法:我们随访了未感染过COVID-19信使RNA(mRNA)疫苗的受试者的抗体水平(VN,n=100)分两个阶段:〜1.4的I期(P-I)和〜5.3个月的II期(P-II)。将抗体水平与未接种疫苗和自然感染的受试者的抗体水平进行比较(NI,n=40),感染后约1.7(P-1)和5.2(P-II)个月。中和抗体(NTAB),抗S-RBD-IgG,测量-IgM和抗-S-IgA同种型。
结果:在P-I时,VN组引起的抗体应答明显高于NI组(P<0.001),除了IgM.在VN组中,在所有同种型中观察到抗体应答显著下降.NTAb水平下降约4倍(P<0.001),抗S-RBD-IgG(~5倍,P<0.001),抗S-RBD-IgM(~6倍,P<0.001)和抗S1-IgA(2倍,P<0.001)。在NI组中,S-RBD-IgM显著但不太稳定的下降(~2倍,P<0.001),NTAb的差异小得多,但差异显著(<2倍,P<0.001)抗S-RBDIgG(<2倍,P=0.005)。与VN组不同,NI组出现持续的抗S1-IgA应答,且无显著下降.抗S1-IgA,与P-1中的NI相比,VN受试者中的NI高约3倍(P<0.001),下降到几乎相同的水平,两组P-II无显著差异。
结论:尽管双剂量mRNA疫苗可提高抗体水平,接种疫苗的个体“加强免疫”相对较短。
Waning protection against emerging SARS-CoV-2 variants by pre-existing antibodies elicited because of current vaccination or natural infection is a global concern. Whether this is due to the
waning of immunity to SARS-COV-2 remains unclear.
We aimed to investigate the dynamics of antibody isotype responses amongst vaccinated naïve (VN) and naturally infected (NI) individuals.
We followed up antibody levels in COVID-19 messenger RNA (mRNA)-vaccinated subjects without prior infection (VN, n = 100) in two phases: phase-I (P-I) at ~ 1.4 and phase-II (P-II) at ~ 5.3 months. Antibody levels were compared with those of unvaccinated and naturally infected subjects (NI, n = 40) at ~ 1.7 (P-1) and 5.2 (P-II) months post-infection. Neutralizing antibodies (NTAb), anti-S-RBD-IgG, -IgM and anti-S-IgA isotypes were measured.
The VN group elicited significantly greater antibody responses (P < 0.001) than the NI group at P-I, except for IgM. In the VN group, a significant
waning in antibody response was observed in all isotypes. There was about an ~ 4-fold decline in NTAb levels (P < 0.001), anti-S-RBD-IgG (~5-fold, P < 0.001), anti-S-RBD-IgM (~6-fold, P < 0.001) and anti-S1-IgA (2-fold, P < 0.001). In the NI group, a significant but less steady decline was notable in S-RBD-IgM (~2-fold, P < 0.001), and a much smaller but significant difference in NTAb (<2-fold, P < 0.001) anti-S-RBD IgG (<2-fold, P = 0.005). Unlike the VN group, the NI group mounted a lasting anti-S1-IgA response with no significant decline. Anti-S1-IgA, which were ~ 3-fold higher in VN subjects compared with NI in P-1 (P < 0.001), dropped to almost the same levels, with no significant difference observed between the two groups in P-II.
Whereas double-dose mRNA vaccination boosted antibody levels, vaccinated individuals\' \'boost\' was relatively short-lived.