I'm really worried..I heard that there are batches of vaccines referred to as "hot lots" that might be dangerous. Do hot lots exist?
No. There is no evidence that there are safety differences from one vaccine batch to another. Vaccine reactions are routinely reported to the federal government Vaccine Adverse Event Reporting System (VAERS).
While there’s a common belief that large numbers of VAERS reports come from certain batches of vaccine (so-called hot lots), the VAERS data have never found a vaccine lot to be unsafe.
Keep in mind that every vaccine lot is tested for safety by its maker. Both the Food and Drug Administration and the Centers for Disease Control and Prevention (CDC) conduct ongoing surveillance to make sure vaccines are safe.