Clinico-Demographic Profile of Vaccinated/Partially Vaccinated Versus Non-Vaccinated Covid-19 Cases in Second Wave of India

BACKGROUND As of 20th November 2021, 29.1 % (40.1 crore) of the population has been completely vaccinated while 55.6 % (76.6 crore) of the population have received at least one dose of vaccine. Infection despite vaccination (vaccine breakthrough) has been reported, but characteristics of these infection regarding clinico demographic profile, severity of disease and mortality in the fully vaccinated, partially vaccinated and non-vaccinated groups are not well described; during the second Covid-19 wave in India from April to June 2021 when the highly transmissible delta variant predominated. METHODS This was an observational analysis of epidemiological features, clinical manifestations and outcome of Covid-19 positive patients during the second wave. Vaccination status, CT scoring, RT PCR reports, bio markers like CRP, d dimer, IL-6 were recorded. Statistical analysis was done using Epi Info version 7.2.1.0 statistical software. The study was approved by institutional research and ethical committee. RESULTS 182 Covid patients had received only one dose, 24 were fully vaccinated and 24 were unvaccinated. Unvaccinated patients were younger than vaccinated people (p < 0.001) CT severity scoring were relatively higher in unvaccinated patients as compared to vaccinated patients. (p = 0.003). 92.3 % of our vaccinated patients’ group were treated on OPD basis while in unvaccinated patients 41.7 % required hospitalisation. Biomarkers (CRP, D-DIMER and IL-6) were also deranged to a lesser severity among vaccinated and partially vaccinated study population as compared to unvaccinated individuals. Death occurred in 8.3% of unvaccinated patients and only 1.1 % of partially vaccinated patients, while no mortality occurred in fully vaccinated patients. CONCLUSIONS We can conclude that vaccines play a critical role in preventing serious Covid-19 illness and remain highly effective in preventing Covid-19 hospitalizations and the biomarkers (CRP, d dimer, IL-6) can be used in the risk stratification of Covid-19 infections. KEY WORDS Second Covid-19 Wave in India, Delta Variant, Vaccine Breakthrough Infections, Hospitalisations, Bio Markers, D Dimer, CRP, IL-6.