key: cord-0845498-3yqivwlh authors: Díaz, Luis Antonio; Fuentes‐López, Eduardo; Lazo, Mariana; Kamath, Patrick S.; Arrese, Marco; Arab, Juan Pablo title: Vaccination against COVID‐19 decreases hospitalizations in patients with cirrhosis: Results from a nationwide analysis date: 2022-02-15 journal: Liver Int DOI: 10.1111/liv.15193 sha: 175c70113e046b0ca077125a1f428b7d2822787f doc_id: 845498 cord_uid: 3yqivwlh nan We used comprehensive information obtained through the national SARS-CoV-2 surveillance program of the Chilean Ministry of Health. Under this program, all suspected cases of COVID-19 were notified to the ministry, including data on comorbidities and hospitalizations. We included both confirmed and probable cases of COVID-19 from 3 March 2020 to 30 May 2021. SARS-CoV-2 infection was confirmed by real-time polymerase chain reaction (qPCR) performed by the Chilean Institute of Public Health and certified laboratories. In addition, we updated twice a week the incidence rate and prevalence of comorbidities, including cirrhosis, diabetes, hypertension, chronic kidney disease, asthma and heart failure from the national SARS-CoV-2 surveillance program. Also, we collected the overall vaccination rate during the study period. Using a quasi-experimental design, we assessed the effectiveness of COVID-19 vaccination in decreasing hospitalizations caused by COVID-19 infection. We used regression discontinuity (RD) models with a first-order polynomial and robust bias-corrected inference to estimate the impact of vaccinations as determined by hospitalization rates (recorded as a continuous variable). We estimated the hospitalization rate using a cut-off twice a week, considering the percentage of patients with determined comorbidity admitted during an established period. We defined the first vaccination dose as the date when the vaccination among the overall population began. The effect was estimated beyond 14 days after the first and second vaccination dose. There was a difference of 35 days between both assessments. In an RD design, assuming that there are no other contemporaneous changes, the temporal difference in the outcome could be attributable to the temporal change in the treatment. As demonstrated by the COVID-19 vaccination experience in the USA, several barriers remain to universal acceptance of vaccines. 1, 13 These and other concerns must be addressed during the massive vaccination campaigns planned in other countries if the adoption of vaccines against COVID-19, especially in high-risk groups, is not widely accepted. Our study had some limitations. The absence of individualized data limits the statistical analysis in a quasi-experimental study and the ability to control for confounding factors. Also, the severity (Child-Pugh or MELD scores) and the aetiology of cirrhosis are not available. The impact of liver disease aetiology (i.e. ALD versus non-alcoholic fatty liver disease) on the risk of hospitalization and death could not be ascertained. Because of the nature of the database, there may have been patients with cirrhosis, especially those with compensated cirrhosis, who may not have been identified with this comorbidity. Finally, we did not assess the prevalence of SARS-CoV-2 variants in our country. It is an important point since some variants could decrease COVID-19 effectiveness. Further studies are necessary to assess the effects of virus variants on COVID-19 vaccines efficacy. In conclusion, we observed in our nationwide study an association between vaccination against COVID-19 and a lower hospitalization F I G U R E 1 The absolute reduction in hospitalization rates after administration of one and two vaccine doses according to the presence of comorbidities in Chile Beyond politics -promoting Covid-19 vaccination in the United States Risk factors of critical & mortal COVID-19 cases: a systematic literature review and meta-analysis Outcomes following SARS-CoV-2 infection in patients with chronic liver disease: an international registry study Systematic review with meta-analysis: liver manifestations and outcomes in COVID-19 COVID-19 and indirect liver injury: a narrative synthesis of the evidence COVID-19 risk, disparities and outcomes in patients with chronic liver disease in the United States BNT162b2 mRNA Covid-19 vaccine in a Nationwide mass vaccination setting SARS-CoV-2 vaccination in patients with liver disease: responding to the next big question Association of BNT162b2 mRNA and mRNA-1273 vaccines with COVID-19 infection and hospitalization among patients with cirrhosis Analysis of antibody responses after COVID-19 vaccination in liver transplant recipients and those with chronic liver diseases Coordinated cellular and humoral immune responses after two-dose SARS-CoV2 mRNA vaccination in liver transplant recipients Three doses of an mRNA Covid-19 vaccine in solid-organ transplant recipients An uncertain public -encouraging acceptance of Covid-19 vaccines