Postmarketing surveillance: How vaccine safety is monitored after authorization.

What is vaccine postmarketing surveillance?

Vaccine postmarketing surveillance is the tracking of vaccine safety after they have been authorized for use in the population. There are now three COVID-19 vaccines authorized in the United States. Before authorization, all three were found to be safe and effective at preventing COVID-19 sickness in clinical trials. Now that these vaccines are mass distributed to the public, information about their safety is still being collected.

How are adverse events monitored?

One monitoring system in the US is the Vaccine Adverse Event Reporting System (VAERS), where patients and doctors report any problems that happen after the vaccine. The VAERS is run by the Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC). Reports are completed online and include information like the problem and outcome, timing, and type of vaccine. The FDA and CDC then carefully review reports to see if the vaccine could have caused the event and to see if similar events have been reported. Most events are not caused by the vaccine, but all reports are taken seriously. 

Where can I report a serious side effect I had after receiving the COVID-19 vaccine?

The CDC has created a smartphone app called V-safe to check how people are doing after receiving their vaccine. Once people sign up and provide information on their vaccination, the app will automatically text a health check-in after each vaccine dose. If a person reports any problems, they are asked to tell their doctor and the VAERS system.

What if patients and doctors do not report adverse events?

The VAERS and V-safe systems rely on people or their doctors to report any problems. For this reason, these are called passive systems. The issue with passive systems is that not all problems are reported. Two other systems that collect information from healthcare records are also used: the Vaccine Safety Datalink (VSD) and the Biologics Effectiveness and Safety System (BEST). 

In summary, the United States has multiple systems in place to check on vaccine safety. Some rely on people or their doctors to report any problems, while others use healthcare data. All these systems work together to make sure that the COVID-19 vaccines are safe for use.

Last update: April 15, 2021 at 5:45PM (ET) 

Science review: SGB, BK