Kinetics of immune responses to the AZD1222/Covishield vaccine with varying dose intervals in Sri Lankan individuals. Issue 4 (22nd March 2022)

• Record Type: Journal Article
• Authors: Jeewandara, Chandima; Aberathna, Inoka Sepali; Gomes, Laksiri; Pushpakumara, Pradeep Darshana; Danasekara, Saubhagya; Guruge, Dinuka; Ranasinghe, Thushali; Gunasekera, Banuri; Kamaladasa, Achala; Kuruppu, Heshan; Somathilake, Gayasha; Dissanayake, Osanda; Gamalath, Nayanathara; Ekanayake, Dinithi; Jayamali, Jeewantha; Jayathilaka, Deshni; Mudunkotuwa, Anushika; Harvie, Michael; Nimasha, Thashmi; Wijayamuni, Ruwan; Schimanski, Lisa; Rijal, Pramila; Tan, Tiong K.; Dong, Tao; Townsend, Alain; Ogg, Graham S.; Malavige, Gathsaurie Neelika
• Is Part Of: Immunity, inflammation and disease. Volume 10:Issue 4(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-03-22
• Subjects: antibodies -- AZD1222 -- COVID‐19 -- dosing intervals -- immunogenecity -- T cells -- vaccines -- variants; Immunology -- Periodicals; Immunity -- Periodicals; Inflammation -- Periodicals; 616.079
• DOI: 10.1002/iid3.592
• Languages: English
• ISSNs: 2050-4527

Abstract

Abstract: Background: To understand the kinetics of immune responses with different dosing gaps of the AZD1222 vaccine, we compared antibody and T cell responses in two cohorts with two different dosing gaps. Methods: Antibodies to the SARS‐CoV‐2 virus were assessed in 297 individuals with a dosing gap of 12 weeks, sampled 12 weeks post second dose (cohort 1) and in 77 individuals with a median dosing gap of 21.4 weeks (cohort 2) sampled 6 weeks post second dose. ACE2‐blocking antibodies (ACE2‐blocking Abs), antibodies to the receptor‐binding domain (RBD) of variants of concern (VOC), and ex vivo T cell responses were assessed in a subcohort. Results: All individuals (100%) had SARS‐CoV‐2‐specific total antibodies and 94.2% of cohort 1 and 97.1% of cohort 2 had ACE2‐blocking Abs. There was no difference in antibody titers or positivity rates in different age groups in both cohorts. The ACE2‐blocking Abs ( p < .0001) and antibodies to the RBD of the VOCs were significantly higher in cohort 2 compared to cohort 1. 41.2% to 65.8% of different age groups gave a positive response by the hemagglutination assay to the RBD of the ancestral virus and VOCs in cohort 1, while 53.6%–90% gave a positive response in cohort 2. 17/57 (29.8%) of cohort 1 and 17/29 (58.6%) of cohort 2 had ex vivo interferon (IFN)γ ELISpot responses above the positive threshold. The ACE2‐blocking antibodies (Spearman's r = .46, p = .008) and ex vivo IFNγ responses (Spearman's r = .71, p < .0001) at 12 weeks post first dose, significantly correlated with levels 12 weeks post second dose. Conclusions: Both dosing schedules resulted in high antibody and T cell responses post vaccination, although those with a longer dosing gap had a higher magnitude of responses, possibly as immune responses were measured 6 weeks post second dose compared to 12 weeks post second dose. Abstract : We found that those who had a wider dosing gap (20 weeks compared to 12 weeks) had higher antibody and T cell responses, 6 months post first dose of the AZD1222 vaccine, possibly as immune responses were measured 6 weeks post second dose compared to 12 weeks post second dose.