As of 12 May 2020, there are 283,153 deaths for COVID-19 worldwide according to the World Health Organization (WHO). Patients with cirrhosis, acute-on-chronic liver failure (ACLF), and hepatocellular carcinoma appear to be at high risk of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection and progress to most severe forms of COVID-19 with at least 5-fold increased risk of death.

Vaccination against SARS-CoV-2 has been proven effective to reduce hospitalization and death from COVID-19 in individuals without immunosuppression, but existing data demonstrate that a markedly reduced fraction of transplant recipients are able to mount positive antibody responses after 1 or 2 doses of SARS-CoV-2 messenger RNA (mRNA) vaccine. There are relatively few data demonstrating the effectiveness of these vaccines in preventing breakthrough infections in liver transplant recipients. Moreover, there are few data to measuring the antibody response, or degree of protection from vaccination, in patients with cirrhosis.

More scientific evidence to guide effective clinical management and vaccination strategies for patients with chronic liver disease

In order to fill this knowledge gap, EF CLIF in collaboration with the Foundation for Liver Research, European Association for the Study of the Liver (EASL), European Liver and Intestine Transplant Association (ELITA) and European Patients’ Association (ELPA) joined efforts to assess the degree of protection against COVID-19 after the primary vaccination schedule and subsequent booster in patients with cirrhosis, autoimmune liver disease and post-liver transplantation.

As this is a prospective observational study, the research team recruits participants over time. In all three groups, demographic data, medical history, comorbidities and medications will be collected and blood samples for laboratory analyses processed.

The research team is also studying children aged 12–16 with liver disease or liver transplantation, for their responses to COVID-19 vaccination. These data are of particuarvalue, since very few studies have been conducted in pediatric patients.

Gautam Mehta, Principal Investigator for COBALT and based at University College London, UK, explained that the results from the COBALT study “will provide valuable insight into factors predicting vaccine response and new infection in these vulnerable patients. In particular, we want to know if the vaccines protect against the newer variants, such as Omicron. We believe the data will impact how booster vaccines are used in the future for liver patients”.

This study is supported by the European Foundation for the Study of Chronic Liver Failure.