D0481 - Cost Effectiveness of Checking Immunity for HAV Before Vaccination in HCV Patients

Jason Farrell, DO¹, Sara Gaines, PharmD, BCPS¹, Benyam Addissie, MD^2
1Geisinger Medical Center, Danville, PA; ²Geisinger Health System, Danville, PA

Introduction: Vaccination against Hepatitis A virus (HAV) is recommended for all patients with chronic liver diseases including chronic hepatitis C virus (HCV) infection. At our institution, we screen HCV patients’ HAV immunity and vaccinate those who are not immune. We confirm lack of immunity by serology if previous vaccination is not documented. An alternative approach that some centers with low HAV seropositivity rate have taken is empirically vaccinating all vaccine candidates and eliminating the cost of serology tests. In this study, we compared the cost associated with HAV vaccination after confirming absence of immunity with the cost of empiric vaccination of all HCV patients without checking immunity. We also developed a simple calculation to find the most cost-effective strategy for any cohort.

Methods: Retrospective analysis of patients referred to hepatology clinic for HCV treatment from March 2021 to March 2022 and underwent screening for HAV immunity was done. We assessed prevalence of HAV immunity in this cohort, cost associated with testing for immunity by serology, and cost of administration of vaccination. We compared the cost associated with the two strategies.

Results: 251 patients were referred for HCV treatment in the study period. 30 patients had documentation of previously completed HAV vaccination series. Of the 221 remaining patients, 151 patients (68.3%) had negative and 70 patients (31.7%) had positive anti-HAV antibodies. The patient charge accrued for antibody testing at our facility for Hepatitis A IgG & IgM is estimated to be 10.3% of the cost of a complete vaccination course. Total cost of vaccination of the 151 patients was 21.4% less expensive than empiric vaccination of all 221 patients.

Discussion: The cost associated with hepatitis A vaccination includes cost of serology to confirm absence of immunity and cost of vaccine administration for those in whom it is needed. Vaccinating all patients empirically would be more economical only if the seropositivity rate is less than the ratio of cost of serology test to vaccine administration charges. Based on our results, we found it to be more cost-effective to verify absence of immunity before vaccinating our HCV patients. A possible limitation of this study is availability of vaccination records of all patients which may have led to serology tests on more patients. However, many patients receive care within our integrated system.


Disclosures:


Jason Farrell, DO¹, Sara Gaines, PharmD, BCPS¹, Benyam Addissie, MD². D0481 - Cost Effectiveness of Checking Immunity for HAV Before Vaccination in HCV Patients, ACG 2022 Annual Scientific Meeting Abstracts. Charlotte, NC: American College of Gastroenterology.