Effects of the Second Dose of COVID-19 Vaccines in Patients with Autoimmune Rheumatic Diseases with Hybrid Immunity

We aimed to determine the effect of the second dose of a COVID-19 vaccine by comparing antibody levels and the neutralization between single versus double vaccination in individuals with AIRDs who were previously infected with COVID-19. It’s a prospective cohort study in which patients with AIRDs previously infected with COVID-19, who had received at least one dose of either AZD1222(N=410) or BBV152 (N=30) were included and stratified based on the number of vaccine doses (V) and order of occurrence of infection (I) into four groups: I +V, I+V+V, V+I, V+V+I. Anti-RBD (Receptor Binding Domain) antibodies (n=230) and virus neutralisation was measured (n=79) along with a paired sera analyses for 49 samples. The highest levels of anti-RBD antibodies were observed in the V+V+I group(18219±7702 IU/ml) with no significant difference between those who received 2 doses of vaccine(I+V+V, 10392±8514 IU/ml) and those who had received only one dose of (I+V, 8801±8122IU/ml). The neutralisation assays showed that only the hybrid immunity sera could neutralise the omicron variant. AZD1222 hybrids performed better as compared to BBV152 hybrids for the omicron variant. The analysis of the paired sera showed that after the second vaccine dose, antibody titres decreased significantly [9626(IQR:4575-18785) to 5781(2484-11906);p<0.001]. Delta neutralization was unaffected by the second dose however, the omicron neutralization was significantly reduced after the second dose [45.7(5.3 - 86.53) % to 35(7.3-70.9) %; p=0.028]. In conclusion, previously infected individuals with COVID-19 may not need a second vaccine dose.Funding: None to declare. Conflicts of Interest: SA has received honorarium as speaker from Pfizer, Dr Reddy’s, Ciplaand Novartis (outside of the current work). The other authors declare no conflicts of interest.Ethical Approval: It was a prospective observational cohort study carried out at the Centre for Arthritis and Rheumatism (CARE), Kochi, Kerala after obtaining ethics approval from Sree Sudheendra Medical mission and informed consent from all participants.