Author Response: Stroke Among SARS-CoV-2 Vaccine Recipients in Mexico: A Nationwide Descriptive Study.

Abstract

We greatly appreciate the insightful comments by Dr. Taccetta on our article.1 We agree that passive epidemiologic surveillance is less likely to detect incidence, which is why we only reported the observed incidence and not a rate or ratio. This is a limitation we acknowledged in our article.1 In addition, concerning the 30-day timeframe from immunization to event detection in our study, we recognize that some neurologic events such as cerebral venous thrombosis (CVT) and Guillain-Barré syndrome (GBS) may occur up to 42 days after immunization. However, as stated in the Methods section, the World Health Organization's noted operational definition for surveillance of adverse events following immunization (AEFI) in our country only includes events occurring within the first 30 days after immunization.2,3 Hence, we were unable to detect or collect data on those cases occurring beyond the time frame specified by our legislature—a limitation that we also acknowledged as a potential selection bias. Recently, the increasing number of vaccine-induced thrombotic thrombocytopenia with CVT and GBS reports worldwide, especially with adenovirus-based vaccines,4,5 has compelled the expansion of our country's AEFI surveillance time frame to consider cases occurring within the first 42 days. We plan to consider this information in future reports.