The Centers for Disease Control (CDC) and the Food and Drug Administration (FDA) are working together to make sure our vaccines are safe. In pursuit of that end, the organizations want to know about adverse health events that might occur after a vaccination. A new reporting system has been put in place for use by the general public called VAERS (Vaccine Adverse Event Reporting System). There is more information in the video about exactly what the website is for, why you might use it and how to use it.
It is important to note that this is an information gathering site, and will not be able to answer questions for those that submit reports. However, the CDC and FDA want to know about what people might be experiencing, and can use that data to ensure the health of the general public. They have made it fairly simple and convenient to make sure they receive potentially important information.