Impact of COVID-19 vaccine doses and viral waves on inflammatory and immunological responses to COVID-19 infections in India

BackgroundInvestigation of the effect of SARS-CoV-2 variants and COVID-19 vaccination on inflammatory and immune response to SARS-CoV-2 infection is limited in South Asia. ObjectivesWe aimed to examine the impact of COVID-19 vaccination and waves of COVID- 19 on inflammatory and immunological biomarkers among COVID-19 patients in India. MethodsThis cross-sectional analysis used baseline data from a randomized controlled trial of vitamin D and zinc during COVID-19 infection in India (N=181). Blood samples and data regarding vaccination doses were collected. The second (Delta) or third (Omicron) wave was determined by date of enrolment. Mixed effects linear regression with robust standard errors was used to examine associations between COVID-19 vaccination dose or wave at enrolment and C-Reactive Protein (CRP), ferritin, lactate dehydrogenase (LDH), D-dimer, interleukin-6 (IL-6), angiopoietin-2 (Ang-2), soluble triggering receptor expressed on myeloid cells-1 (sTREM-1), immunoglobulin G (IgG) and immunoglobulin M (IgM). ResultsCompared to no vaccination, full vaccination was associated with lower LDH (P<0.001), D-dimer (P=0.521) and Ang-2 (P=0.046), and higher IgG levels (P<0.001). Partial vaccination was associated with lower IL-6 (P=0.040) and higher IgG (P<0.001). Enrolment during the third wave was associated with lower IL-6 (P<0.001), CRP (P=0.056), IgM (P=0.013), and IgG (P<0.001), but higher D-dimer levels (P<0.001). ConclusionsCOVID-19 vaccination status and SARS-CoV-2 variant influence the inflammatory and immunologic response during SARS-CoV-2 infection, contributing to the severity of clinical presentation.