In that study of postvaccine problems reported to the Vaccine Adverse Events Reporting System (VAERS) over a 2.4-year period, reports of syncope and venous thromboembolism after vaccination with Gardasil exceeded the expected background rates. The company responded that Gardasil has not been associated with an increase in thromboembolic events, and that the events reported have been in people with risk factors for thromboembolism.