Many types of products including cars, toys, and food products are sometimes recalled for short times or withdrawn permanently from the market because they don’t work properly or pose a safety risk.
Although every vaccine goes through years of testing before being used, vaccines or vaccine lots (specific batches) can also be withdrawn or recalled.
There have been only a few vaccine recalls or withdrawals due to concerns about either how well the vaccine was working or about its safety. Several vaccine lots have been recalled in recent years because of a possible safety concern before anyone reported any injury. Rather, the manufacturer’s quality testing noticed some irregularity in some vaccine vials. In these cases, the safety of these vaccines was monitored continuously before and after they were in use.
The Centers for Disease Control and Prevention analyzed reports to the Vaccine Adverse Event Reporting System to search for any side effects that might have been caused by the irregularity and found none. Any time such an irregularity is found in a vaccine lot that could make it unsafe, the manufacturer, in collaboration with the Food and Drug Administration, will recall it immediately.
Source:
CDC: Vaccine Recalls