Important: VAERS reports alone cannot determine if a vaccine caused an adverse event. Reports may contain incomplete, inaccurate, or unverified information. Correlation does not equal causation.
Key events in the history of vaccine safety monitoring in the United States — from early manufacturing disasters to modern surveillance systems. This timeline shows how today's safety infrastructure was built, often in response to problems.
Improperly inactivated polio vaccine from Cutter Laboratories caused 40,000 polio cases, 200 children paralyzed, and 10 deaths. Led to stricter manufacturing oversight.
Explore related data →Mass swine flu vaccination campaign halted after ~450 cases of Guillain-Barré Syndrome detected. Demonstrated the need for ongoing safety monitoring.
Explore related data →Congress created the National Vaccine Injury Compensation Program (VICP) and mandated reporting of certain adverse events. Foundation of the modern vaccine safety system.
Explore related data →The Vaccine Adverse Event Reporting System launched as a joint CDC/FDA program. Now contains 1.98M+ reports and is the primary public database for adverse event monitoring.
Explore related data →Andrew Wakefield published a fraudulent study linking MMR vaccine to autism. The paper was retracted in 2010 and Wakefield lost his medical license, but anti-vaccine movements grew.
Explore related data →First rotavirus vaccine (RotaShield) withdrawn after VAERS detected intussusception risk — about 1 in 10,000 infants. A success story for the safety monitoring system.
Explore related data →Gardasil approved for cervical cancer prevention. Generated significant reports in VAERS, with fainting (syncope) identified as a notable side effect in adolescents.
Explore related data →The Lancet fully retracted the 1998 MMR-autism study. Multiple large studies found no link between MMR and autism. Wakefield was struck off the UK medical register.
Explore related data →VSD expanded to cover ~12 million people across 9 healthcare organizations, enabling active surveillance that complements VAERS passive reporting.
New recombinant shingles vaccine (Shingrix) approved. Much more effective but with stronger side effects — 80%+ report injection site reactions. Generated significant VAERS reports.
Explore related data →Pfizer and Moderna mRNA vaccines received Emergency Use Authorization. The largest vaccination campaign in history began, with unprecedented VAERS reporting to follow.
Explore related data →VAERS and v-safe detected myocarditis/pericarditis signal in young males after mRNA COVID vaccines. Risk confirmed at ~1 in 5,000-10,000 for males 16-24 after dose 2.
Explore related data →CDC/FDA recommended pausing Johnson & Johnson COVID vaccine after 6 cases of rare blood clotting (TTS) among 6.8 million doses. Pause lifted after 10 days with updated guidance.
768,706 VAERS reports filed in a single year — more than 10x the typical annual volume. Driven by massive COVID vaccination campaign and heightened public awareness.
Explore related data →Johnson & Johnson voluntarily withdrew its COVID vaccine from the U.S. market, citing low demand. The TTS blood clotting risk, though rare, contributed to low uptake.
First RSV vaccines approved for adults 60+. Abrysvo and Arexvy entered the market, adding new data streams to VAERS.
HHS/RFK Jr. administration announced development of AI tools for analyzing VAERS data, signaling renewed government focus on vaccine safety monitoring.
Vaccine safety monitoring has evolved dramatically over 70 years. Today's system — VAERS, VSD, CISA, and v-safe — represents multiple layers of surveillance that didn't exist for most of vaccine history.
Every withdrawal and detected signal on this timeline is evidence that the system works: problems are found and addressed. The challenge is communicating that monitoring process to a public that often hears about risks without the context of how they were detected and resolved.