Hybrid Immunity Versus Vaccine-Induced Immunity Against SARS CoV2 in Patients With Autoimmune Rheumatic Diseases

Abstract

Introduction: Single-dose COVID-19 vaccines in healthy individuals with past COVID-19 infections seem to provide better immunity than double doses in COVID-19 unexposed individuals. However, it is not known whether the same is true for patients with autoimmune rheumatic diseases (AIRD) who are on immunosuppressants.Methods: We identified 30 patients with AIRD who took a single dose of the ChAdOx1 vaccine post-COVID-19 infection. Age, sex and disease similar patients were enrolled in to three groups of 30 each who had (1) past infection with COVID-19 but no vaccine, (2) a single dose of ChAdOx1 and (3) double doses of ChAdOx1. Sera were collected from each patient approximately 30 days after last vaccine dose or since the onset of COVID19 symptoms (in the unvaccinated group). Antibodies to spike protein were estimated and virus neutralization potential of sera was tested.Results: Baseline characteristics including drug usage was similar between the groups. Seroconversion occurred in 25(83%), 23(77%), 27(90%), and 30(100%) in natural infection, single-dose vaccine, double dose vaccine, and infection +single dose vaccine groups respectively. Mean antibody titres (10076.8±8998) in the last group were at least 6-100x higher than in the other 3 groups. Also, the infection +vaccine group had the highest neutralization potential of 83.37 % as compared to 45.4% in the fully vaccinated group.Conclusion: The hybrid immunity with a single dose of the vector-based vaccine post-infection seems to be superior to double dosage of the vaccine in patients with AIRD. A universal vaccination strategy involving a single dose of vaccine for all individuals with previous COVID-19 infection seems to be effective in these patients also.