Gardasil is a 3-dose (injection) vaccine. , there were more than 57 million doses distributed in the United States, though it is unknown how many were administered. There have been 22,000 Vaccine Adverse Event Reporting System (VAERS) reports following the vaccination. Ninety-two percent were reports of events considered to be non-serious (e.g., fainting, pain and swelling at the injection site (arm), headache, nausea and fever), and the rest were considered to be serious (death, permanent disability, life-threatening illness and hospitalization). However, VAERS reports include any reported effects whether coincidental or causal. In response to concerns regarding the rates of adverse events associated with the vaccine, the CDC stated: "When evaluating data from VAERS, it is important to note that for any reported event, no cause-and-effect relationship has been established. VAERS receives reports on all potential associations between vaccines and adverse events."