When revaccination is recommended: An evaluation of non-guideline poliovirus serology testing in Alberta, Canada

Background: The National Advisory Committee on Immunization (NACI) advises against routine poliovirus serology (POLV-S) testing for poliovirus (POLV) immunity, recommending age-appropriate revaccination when immunity is unknown. POLV-S tests strain laboratory resources, result in unnecessary phlebotomy, and are frequently canceled due to no primary indication. This study assessed more than one year of provincial POLV-S requests to identify gaps in adherence to national guidelines. Methods: Data on POLV-S requests from May 1, 2023, to December 31, 2024, were obtained from the laboratory information system. Patient demographics, physician specialty, years of experience, patient history, indication(s) for testing, availability of vaccine records, and additional serologies ordered were analyzed. Results: Of 108 POLV-S requests (requested by 77 physicians), the median patient age was 34.5 years. All ordering physicians were general practitioners. Three (2.8%) requests were for POLV-S alone; 105 (97.2%) included a median of 7 additional serology tests, most commonly measles, rubella, and mumps IgG (89.8%–90.7%). Patient history was absent in 86 (79.6%) requests. Testing was primarily for employment (45.5%), occupational health forms (27.3%), immigration (13.6%), and immunity verification (13.6%). Vaccine records were available for 50 (46.3%) patients; of these, 56% lacked documentation of a POLV vaccine date. Conclusion: Our findings highlight the need to ensure adherence to NACI guidelines to reduce unnecessary POLV-S testing. Education surrounding the lack of availability of POLV-S testing and the safety and efficacy of revaccination in patients with unknown immunization history will improve laboratory efficiency and ensure immunity to POLV.