Objective To identify the rates of neurological events following administration of mRNA (Pfizer, Moderna) or adenovirus vector (Janssen) vaccines in the U.S. Methods We used publicly available data from the U.S. Vaccine Adverse Event Reporting System (VAERS) collected between January 1, 2021 and June 14, 2021. All free text symptoms that were reported within 42 days of vaccine administration were manually reviewed and grouped into 36 individual neurological diagnostic categories. Post‐vaccination neurological event rates were compared between vaccine types and to age‐matched baseline incidence rates in the U.S. and rates of neurological events following COVID. Results Of 306,907,697 COVID vaccine doses administered during the study timeframe, 314,610 (0.1%) people reported any adverse event and 105,214 (0.03%) reported neurological adverse events in a median of 1 day (IQR0‐3) from inoculation. Guillain‐Barre Syndrome (GBS), and cerebral venous thrombosis (CVT) occurred in fewer than 1 per 1,000,000 doses. Significantly more neurological adverse events were reported following Janssen (Ad26.COV2.S) vaccination compared to either Pfizer‐BioNtech (BNT162b2) or Moderna (mRNA‐1,273; 0.15% vs 0.03% vs 0.03% of doses, respectively, p < 0.0001). The observed‐to‐expected ratios for GBS, CVT and seizure following Janssen vaccination were ≥1.5‐fold higher than background rates. However, the rate of neurological events after acute SARS‐CoV‐2 infection was up to 617‐fold higher than after COVID vaccination. Interpretation Reports of serious neurological events following COVID vaccination are rare. GBS, CVT and seizure may occur at higher than background rates following Janssen vaccination. Despite this, rates of neurological complications following acute SARS‐CoV‐2 infection are up to 617‐fold higher than after COVID vaccination. ANN NEUROL 2022;91:756–771

Background: In certain cases, anti-idiotypic antibodies that recognize an antigen-combining site of an antibody can mimic the structure and/or function of certain nominal antigens. This feature makes them particularly useful if conventional experimental approaches fail to fulfil expectations, especially when the molecule of interest is infectious, toxic or difficult to isolate and purify. We suggest the application of an anti-idiotype concept to the field of prion biology, with the aim of evoking a humoral immune response against the pathological isoform of the prion protein (PrP Sc ). Different ways to induce anti-idiotypic responses were studied in mice and chickens using various forms of V5B2, a PrP Sc -specific monoclonal antibody we have described previously.

The small number of Slovenian cases of sporadic Creutzfeldt-Jakob disease during the last 19 years has shown a pronounced increase in incidence, reflecting improved surveillance, and a high female to male ratio, where female cases are more than twice as numerous as male cases.