Maria Pilar Ballester, postdoctoral researcher at the Digestive Disease Department in the Hospital Clínico Universitario de Valencia, Spain, presented data in support of a reduced risk of COVID-19 infection within 12–24 weeks of vaccination in patients with cirrhosis, autoimmune liver disease or post-liver transplant, a sub-study embedded within the COBALT study at the 47th Annual Congress of the Spanish Association for the Study of the Liver (AEEH) that took place on 25–27 May 2022 in Madrid, Spain.

In a cohort of 205 patients which included patients with cirrhosis (31%), autoimmune liver disease (32%) or who received a liver transplant (37%), 3 patients tested positive for SARS-CoV-2 after a second dose of COVID-19 vaccine and only 1 patient required hospitalization. Patients with a history of COVID-19 were excluded from the sub-study and clinical factors such as sex, etiology, or immunosuppressive treatment appeared not to be associated with the risk of infection. No relationship was found between infection and prognosis of cirrhosis based on the MELD and Child-Pugh scores – two scores that are traditionally used to assess the severity of liver dysfunction and predict patient survival. Biochemical markers of liver or kidney function were not significantly associated with the risk of infection either.

“These results are among the first prospective data for COVID-19 vaccine efficacy for chronic liver disease and liver transplant patients, and as such, should be interpreted with caution”, explained Ballester. “In our sample, the short-term risk of COVID-19 infection in vaccinated patients was 1.5%, which is lower than that reported in retrospective studies”, she added. Besides these promising results, further analysis of our data will help to identify the actual risk of infection in patients with chronic liver disease, the durability of protection against the virus after COVID-19 vaccination and timing to get a vaccine booster dose.

Ballester’s abstract was selected to be presented to the broader audience of the congress in a poster blast session.

The COBALT study is sponsored by EF CLIF and M.P.B. supported by a Río Hortega grant (CM19/00011) from the Instituto de Salud Carlos III.

Other authors on the study are Javier Ampuero, Salvatore Piano, Ângela Carvalho-Gomes, Elena Diago-Sempere, María del Carmen Rico, Eva Román, Iván Sahuco, Yolanda Sánchez, Elisabet Sánchez, Ariadna Bono, Vicente Arroyo, Paolo Angeli, Cristina Sánchez, Eva Usón, Shilpa Chokshi, Rajni Sharma, Antonio Riva, Amir Gander, Germán Soriano, José Luis Calleja, Marina Berenguer, Rajiv Jalan, and Gautam Mehta.

Publication information

Ballester, M.P., Ampuero, J.; Piano, S.; Carvalho-Gomes, A.; Diago-Sempere, E.; Rico, M.d.C.; Román, E.; Sahuco, I.; Sánchez, Y.; Sánchez, E.; Bono, A.; Arroyo, V.; Angeli, P.; Sánchez, C.; Usón, E.; Chokshi, S.; Sharma, R.; Riva, A.; Gander, A.; Soriano, G.; Calleja, J.L.; Berenguer, M.; Jalan, R., Mehta, G. Risk of COVID-19 infection within 12–24 weeks of vaccination in patients with cirrhosis, autoimmune liver disease or post-liver transplant: A COBALT sub-study. In Book of Abstracts, 47º Congreso Anual de la Asociación Española para el Estudio del Hígado (AEEH2022), Madrid, Spain; Poster 38.