evidence: Serious side effects from Gardasil 9 aren’t common, but they can occur. Call your doctor right away if you have serious side effects. Call 911 if your symptoms feel life threatening or if you think you’re having a medical emergency. [...] Vaccine safety monitoring occurs with each vaccine that is released onto the market. There is a vaccine reporting system in place to collect information about any side effects that you may experience from a vaccine. This system is called Vaccine Adverse Event Reporting System (VAERS) and is accessible to patients, pharmacists, and doctors. If you experience a side effect that you believe is from a vaccine, you should report it to VAERS through the website. [...] The most common side effects that can occur from a Gardasil 9 vaccine include pain, redness, or swelling at the injection site, headache, and fever. These side effects are very similar to side effects you may experience from other inactive vaccines.