Influenza Vaccination Does Not Increase Risk for Guillain-Barré Syndrome

The approval is based on evidence that the vaccine can prevent anogenital infections, with an ongoing trial looking at throat infection prevention in men likely to be critical for continued approval.
The approval is based on evidence that the vaccine can prevent anogenital infections, with an ongoing trial looking at throat infection prevention in men likely to be critical for continued approval.
Study authors identified and evaluated a statistical signal for an increased risk of Guillain-Barré Syndrome in days 1-42 after 2018-2019 high-dose influenza vaccine administration.

The benefits of influenza vaccines outweigh the insignificant risk for Guillain-Barré syndrome (GBS) following influenza vaccinations, according to a study published in the Journal of Infectious Diseases.

During the 2018 to 2019 influenza season, the Vaccine Safety Datalink (VSD), a collaborative project between the CDC and 8 integrated health organizations, identified a statistical signal for an increased risk of GBS on days 1 to 42 post-vaccination with the 2018-2019 high-dose influenza vaccine (IIV3-HD). Study authors conducted claims-based self-controlled risk interval analyses among Medicare patients 65 years of age and older to assess this signal.

In total, 7,453,690 patients who received a IIV3-HD vaccination in the early-season and 14,437,945 patients who received a IIV3-HD vaccination at the end-of-season were included and analyzed. Post-vaccination days 8 through 21 and days 1 through 42 were used as risk windows, and post-vaccination days 43 through 84 were used as a control window. Additionally, the VSD performed chart-confirmed analyses on 646,996 IIV3-HD vaccinations.

Results suggested that there are no statistically significant increases in GBS risk following IIV3-HD administration in the 2018-2019 influenza season. In the early-season analyses, there was no statistically significant increase in GBS risk observed in either 8 to 21 days post-vaccination (odds ratio [OR] 1.85; 95% CI, 0.99-3.44) or 1 to 42 days post-vaccination (OR, 1.31; 95% CI 0.78-2.18) risk windows. In the end-of-season analyses, there was no statistically significant increase in GBS risk observed in either 8 to 21 days post-vaccination (OR 1.64; 95% CI 0.92-2.91) or 1 to 42 days post-vaccination (OR, 1.12; 95% CI 0.70-1.79) risk windows.

A final chart review by the VSD identified 1 case of GBS in both the risk (onset, day 1) and control windows, a relative risk of 1.00 (95% CI, 0.06-15.99), and determined it to be statistically insignificant.

While the study does “not exclude an association between 2018-2019 IIV3-HD and GBS,” study authors “determined that, if such risk existed, it was low.” A chart-confirmed VSD result also did not confirm an increased risk of GBS.

Reference

Perex-Vilar S, Hu M, Weintraub E, et al. Guillan-barré syndrome after high-dose influenza vaccine administration in the United States, 2018-2019 Season. J Infect Dis. Published online November 2, 2020. doi: 10.1093/infdis/jiaa543.