Background: Guillain-Barré syndrome (GBS) is often an adverse event of interest in vaccine safety studies, including for respiratory syncytial virus (RSV) vaccines.
Objective: To estimate incidence rates (IRs) of GBS in US adults overall and in key subgroups.
Methods: This study was conducted using US claims data from three national health plans (Carelon Research, CVS Health, Humana) and one integrated delivery system (Kaiser Permanente Southern California). Adults aged ≥18 years in 2017 through 2024 with ≥365 consecutive days of medical and pharmacy coverage were included. GBS cases were identified as an inpatient ICD-10-CM code G61.0 in the principal position. The index date was the hospital admission date, unless an outpatient visit with G61.0 occurred in the prior 7 days, in which case the earlier date was used. Incidence was defined as no GBS diagnosis code (G61.0; G65.0, GBS sequelae) using all available history (any setting, any position). Individuals with GBS were described and IRs were calculated overall and in the following subgroups: individuals with infection in the prior 60 days, vaccination in the prior 21 days, and comorbidities associated with an increased risk of severe RSV-associated lower respiratory tract disease (RSV-LRTD).
Results: Of the 3,663 GBS cases identified, the mean age was 60 years; 28% had a recent infection; 10% had a recent vaccination; and 51% were at increased risk of RSV-LRTD. An overall IR of 2.44 per 100,000 person-years (95% confidence interval [CI] 2.36, 2.52) was calculated, which was generally similar across the study years (IR range 2.35-2.61), with the exception of 2020 (IR 1.89 [1.70, 2.10]). The IRs (95% CI) for the subgroups were: 15.51 (14.59, 16.49) for those with any recent infection, 14.86 (13.34, 16.56) for those with a recent viral infection, 16.83 (15.69, 18.06) for those with a recent bacterial infection, and 4.95 (4.46, 5.50) for those with recent vaccination. Among those at increased risk of RSV-LRTD, the IR was 4.33 (4.14, 4.53) for ages 18-59, 4.88 (4.56, 5.23) for ages 60-74, and 3.67 (3.36, 4.01) for ages ≥75.
Conclusions: Using a claims-based algorithm, the overall GBS incidence rate of 2.44 per 100,000 person-years among US adults in 2017-2024 was consistent with the literature. The lower GBS rate in 2020 observed here has also been reported by others. The rates among those with a recent infection or vaccination were higher than the overall IR, particularly for those with recent infection. Those at increased risk of RSV-LRTD also had a higher rate than adults overall. These findings have implications for studies of GBS among RSV vaccinees and underscore the importance of selecting appropriate comparison groups for vaccine safety studies of GBS.
View the Poster
Bell EJ, Sun J, Horgan C, Back S, Emerton D, Round KE, Walsh ST, Cole DV, Rajbhandari R, Vasquez A, Xu S, Contreras R, Hsu C, Ma Q, DeVries A, Oyedele N, Djibo DA, Wentz AE, Love S-AM, Wu J, Kelly SP, Maro JC, Platt R, Cocoros NM. Incidence Rates of Guillain-Barré Syndrome in Adult Populations in the United States: A Healthcare Database Study to Inform Vaccine Safety Studies. 42nd Annual International Society for Pharmacoepidemiology Conference; 2026 Sep 2; Milan, Italy.
