Currently available mRNA vaccines against COVID-19 effectively reduced infection, hospitalization, and death in U.S. veterans with cirrhosis, a recent study found.
Researchers performed a retrospective cohort study of U.S. veterans with cirrhosis to determine whether mRNA vaccines decreased COVID-19 infection and outcomes. Although mRNA vaccines performed well in clinical trials, patients with cirrhosis, who may also have vaccine hyporesponsiveness, were excluded. The goal of the current study was to determine whether the mRNA vaccines were effective in a population with cirrhosis in real-world practice. The study compared veterans with cirrhosis who received at least one dose of an mRNA COVID-19 vaccine between Dec. 18, 2020, and March 17, 2021, with a propensity-matched control group of unvaccinated patients at similar risk of COVID-19 infection and severe disease. The main outcome measures were COVID-19 infection, as defined by a positive result on polymerase chain reaction, and hospitalization and death due to COVID-19. The study results were published online July 13 by JAMA Internal Medicine.
The study matched 20,037 patients with cirrhosis who had received at least one dose of an mRNA vaccine with 20,037 unvaccinated controls. The median age of vaccinated patients was 69.1 years, and almost all study participants (97.2%) were men. The Moderna vaccine was administered to 10,236 patients (51%), while the Pfizer-BioNTech vaccine was administered to 9,801 (49%). Almost all patients who received a first vaccine dose (99.7%) received a second dose within 42 days of follow-up. Patients in the vaccinated cohort and nonvaccinated controls had similar numbers of COVID-19 infections during days 0 to 7, 7 to 14, 14 to 21, and 21 to 28 after the first mRNA vaccine dose. After 28 days, receipt of one mRNA vaccine dose was associated with a 64.8% reduction in COVID-19 infections and 100% protection against hospitalization or death due to COVID-19 infection. Patients with decompensated versus compensated cirrhosis were less likely to have a reduction in COVID-19 infections after a first vaccine dose (50.3% vs. 66.8%). Receipt of a second dose of mRNA vaccine was associated with a 78.6% reduction in COVID-19 infections and a 100% reduction in hospitalization or death related to COVID-19 after seven days.
Among other limitations, the study included only data from within the Veterans Health Administration, almost all patients were men, and the results could have been affected by residual confounding, the authors noted. They concluded that mRNA vaccines were effective at reducing COVID-19 infection, hospitalization, and death in patients with cirrhosis. “Although these associations suggest lower benefit in this cohort with cirrhosis compared with randomized clinical trials, they appear to be highly associated with a reduction in hospitalization and death due to COVID-19,” the authors wrote. “These findings strengthen the hope that these vaccines may mitigate the effects of the COVID-19 pandemic on individuals with cirrhosis in the US.”