Author:
Akhtar Marjahan,Islam Md. Rashedul,Khaton Fatema,Soltana Umma Hany,Jafrin Syeda Anoushka,Rahman Sadia Isfat Ara,Tauheed Imam,Ahmed Tasnuva,Khan Ishtiakul Islam,Akter Afroza,Khan Zahid Hasan,Islam Md. Taufiqul,Khanam Farhana,Biswas Prasanta Kumar,Ahmmed Faisal,Ahmed Shakeel,Rashid Md. Mamunur,Hossain Md. Zakir,Alam Ahmed Nawsher,Alamgir A. S. M.,Rahman Mahbubur,Ryan Edward T.,Harris Jason B.,LaRocque Regina C.,Flora Meerjady Sabrina,Chowdhury Fahima,Khan Ashraful Islam,Banu Sayera,Shirin Tahmina,Bhuiyan Taufiqur Rahman,Qadri Firdausi
Abstract
BackgroundUnderstanding the characteristics of the humoral immune responses following COVID-19 vaccinations is crucial for refining vaccination strategies and predicting immune responses to emerging SARS-CoV-2 variants.MethodsA longitudinal analysis of SARS-CoV-2 spike receptor binding domain (RBD) specific IgG antibody responses, encompassing IgG subclasses IgG1, IgG2, IgG3, and IgG4 was performed. Participants received four mRNA vaccine doses (group 1; n=10) or two ChAdOx1 nCoV-19 and two mRNA booster doses (group 2; n=19) in Bangladesh over two years.ResultsFindings demonstrate robust IgG responses after primary Covishield or mRNA doses; declining to baseline within six months. First mRNA booster restored and surpassed primary IgG responses but waned after six months. Surprisingly, a second mRNA booster did not increase IgG levels further. Comprehensive IgG subclass analysis showed primary Covishield/mRNA vaccination generated predominantly IgG1 responses with limited IgG2/IgG3, Remarkably, IgG4 responses exhibited a distinct pattern. IgG4 remained undetectable initially but increased extensively six months after the second mRNA dose, eventually replacing IgG1 after the 3rd/4th mRNA doses. Conversely, initial Covishield recipients lack IgG4, surged post-second mRNA booster. Notably, mRNA-vaccinated individuals displayed earlier, robust IgG4 levels post first mRNA booster versus Covishield counterparts. IgG1 to IgG4 ratios decreased with increasing doses, most pronounced with four mRNA doses. This study highlights IgG response kinetics, influenced by vaccine type and doses, impacting immunological tolerance and IgG4 induction, shaping future vaccination strategies.ConclusionsThis study highlights the dynamics of IgG responses dependent on vaccine type and number of doses, leading to immunological tolerance and IgG4 induction, and shaping future vaccination strategies.
Subject
Immunology,Immunology and Allergy