Have any rare or serious adverse events been reported to VAERS or other systems after 2024-2025 COVID shots?
Executive summary
Surveillance systems continued to detect rare but serious events after 2024–2025 COVID-19 vaccines: U.S. monitoring lists anaphylaxis and myocarditis/pericarditis as identified serious adverse events tied to current vaccines [1]. Large multinational studies and reviews published through 2024 flagged very rare neurological and thrombotic events (acute disseminated encephalomyelitis, transverse myelitis, Guillain–Barré syndrome, and cerebral venous sinus thrombosis) and confirmed myocarditis signals for mRNA products [2] [3] [4].
1. What the surveillance systems say: VAERS and formal U.S. monitoring
U.S. systems emphasize that VAERS is an early-warning, open-reporting database that accepts any post‑vaccine health problem and cannot by itself prove causation [5] [6]. The CDC and FDA together state that the safety systems in use through 2024–2025 have identified anaphylaxis and myocarditis/pericarditis as serious adverse events associated with COVID‑19 vaccines currently used in the U.S. [1]. VAERS data releases changed in 2025 to include “secondary” reports in public datasets, a technical change that can make totals look larger though the agency notes these secondary entries relate to already reported events [6].
2. Big-picture international evidence: rare neurological and clotting signals
A 99‑million person multinational Global Vaccine Data Network cohort found small but statistically significant excesses for several rare events: acute disseminated encephalomyelitis, transverse myelitis, Guillain–Barré syndrome (after some viral‑vector vaccines), and cerebral venous sinus thrombosis (CVST) after ChAdOx1 vaccination; the paper and subsequent reporting framed these events as very rare but detectable in large datasets [3] [4] [2]. The BMJ and MedicalXpress coverage of these studies called out transverse myelitis and acute disseminated encephalomyelitis as newly detected rare associations [2] [7].
3. What experts and reviews emphasize about frequency and causation
Systematic reviews and national evidence reviews stress that serious adverse events are uncommon, that establishing direct cause‑and‑effect is challenging, and that surveillance aims to detect signals for follow‑up studies rather than deliver definitive causal proofs [8] [9]. For example, National Academies and peer‑reviewed reviews catalog myocarditis, anaphylaxis, VITT, GBS, and transverse myelitis among the main serious events reported and emphasize clinical assessment and causality workups [8] [9].
4. How to interpret VAERS counts and media reporting
VAERS is a passive system anyone can report to; it is designed to flag possible safety issues for further study, not to provide incidence rates or establish causation [5]. Independent sites that republish VAERS extracts (OpenVAERS, EverlyReport) and some blogs may present raw counts without context; the CDC warns about misusing VAERS data and public commentary has previously highlighted misinterpretation risks [10] [11]. VAERS’s 2025 change to include secondary reports in public downloads can alter apparent counts without representing new events [6].
5. Balancing risk: what agencies and clinicians tell patients
Public health agencies continue to recommend updated vaccines for people at higher risk because vaccines reduce hospitalization and death; clinical guidance and vaccine‑effectiveness studies through 2024–2025 showed benefit, especially in older adults [12] [13]. Clinical sources note common short‑term side effects (sore arm, fatigue, fever) are typical and serious events remain rare and treatable when identified [14] [15].
6. Reporting controversies and open questions
Some reporting shows tension between surveillance findings and policy: news accounts in late 2025 described the FDA’s internal analyses and proposed stricter review standards after examining deaths and other signals, a development that demonstrates how safety signals prompt regulatory re‑examination [16]. Available sources do not mention specific post‑2024–2025 causal attributions beyond the classes of events named by CDC/FDA and the multinational study; more granular, adjudicated counts for 2024–2025 vaccines in other systems are not detailed in the sources provided (not found in current reporting).
7. Practical takeaways for readers
If you’re deciding about an updated COVID shot, weigh the clear benefits in preventing severe COVID documented by vaccine‑effectiveness reviews against the fact that rare serious events—anaphylaxis, myocarditis/pericarditis, and a handful of neurological and thrombotic conditions—have been detected by large surveillance studies and regulatory monitoring [1] [3] [2]. Report any concerning symptoms after vaccination to healthcare providers and to VAERS so regulators can continue signal detection and follow‑up studies [5].