Incidence of Guillain-Barré syndrome following SARS-CoV-2 immunization in Mexico: A nation-wide registry of seven COVID-19 vaccines

Abstract

Background: Guillain-Barré syndrome (GBS) as an adverse event following immunization (AEFI) against SARS-CoV-2 has been linked to a few (ChAdOx1 nCov-19 and Ad26.COV2-S), but not all vaccines, including mRNA-based ones. Epidemiological information on GBS among recipients of other SARS-CoV-2-directed vaccines among Latinx/Hispanic recipients is scarce. Methods: We report GBS incidence per million administered doses from a nationwide Mexican retrospective registry of adult (>18 years) recipients of 81,842,426 doses of seven vaccines against SARS-CoV-2 immunized between December 24, 2020, and October 29, 2021. Cases were collected through a passive epidemiological surveillance system and defined as events occurring within 42 days from immunization. Vaccines were analyzed individually and by vector as either mRNA-based (mRNA-1273 and BNT162b2), adenovirus-vectored (ChAdOx1 nCov-19, rAd26-rAd5, Ad5-nCoV, and Ad26.COV2-S), or inactivated whole-virion-vectored (CoronaVac). Findings: We identified 97 patients (52 [53.6%] males; median age 44 years (interquartile range 33-60), for an overall observed incidence of 1.19/1,000,000 doses (95% confidence interval [CI] 0.97-1.45), higher among Ad26.COV2-S (3.86/1,000,000 doses, 95% CI 1.50-9.93) and BNT162b2 (1.92/1,00,000 doses, 95% CI 1.36-2.71) recipients. The overall interval from vaccination-to-GBS symptoms onset was 10 days (interquartile range 3-17). Preceding diarrhea (> 4 weeks) was reported in 21.6%, and four (4.1%) more had mild COVID-19. Only 18 patients were tested for Campylobacter jejuni infection; 16 (88.9%) were positive. Electrophysiological examinations were performed in 76 (78.4%) patients (axonal in 46 [60.5%] and demyelinating in 25 [32.8%]); variants were similar between platforms. On initial evaluation, 91.8% had a GBS disability score ≥ 3. Seventy-five (77.3%) patients received intravenous immunoglobulin, seven (7.2%) plasma exchanges, and 15 (15.5%) were treated conservatively. There were 10 (10.3%) deaths, and 79.1% of survivors were unable to walk independently at discharge. Interpretation: In our population, GBS was an infrequent AEFI, observed in less than 1.2/1,000,000 administered doses of vaccines against SARS-CoV-2. Observed incidences were higher among Ad26.COV2.S and BNT162b2 recipients individually and for mRNA-vectored vaccines as a group.