Memory T-cell targeted immune response in patients of liver cirrhosis and immunocompetent recipient of ChAdOx1nCoV-19 Vaccine (Covishield)”

Despite the effectiveness of COVID-19 vaccination in reducing the severity of the disease, the demand for booster is increasing in vulnerable populations like elderly and immunocompromised individuals especially with each new wave of COVID-19 in different countries. There is limited data on the sustained immunity against COVID-19 in patients with liver cirrhosis. The study was aimed to compare the T-cell and humoral immune response after one year of ChAdOx1nCoV-19 Vaccine in patients with liver cirrhosis and healthy health-care workers (HCW). This was a prospective observational study including 36 HCW,19 liver cirrhosis patients and 10 unvaccinated individuals. Anti-SARS-CoV-2S antibody, neutralizing antibody and memory T-cell subsets were evaluated by ELISA and flow cytometry respectively in all three groups after one year of initial vaccination. Compared to HCW and unvaccinated individuals, liver cirrhosis patients had significantly depleted T-cells, although CD4:CD8+ T-cell ratio was normal. Significant difference was noted in various memory subsets [effector memory RA (P= 0.141, P= 0.000), effector memory (P= 0.000, P= 0.00), central memory (P= 0.000, P= 0.00), stem cell memory (P= 0.009, P= 0.08) and naïve (P= 0.000, P= 0.02)] of CD4+T and CD8+T respectively. However, on post-hoc analysis no difference was noted in the extent of memory T-cells between cirrhotic patients and HCW. Patients with liver cirrhosis developed comparable memory T-cells after vaccination which can evoke sustainable immune response on reinfection. Therefore, additional vaccine doses may not be necessary for cirrhosis patients.