How are possible side effects from COVID-19 vaccines evaluated and tracked?


A: The vaccines have been shown to be safe (much safer than getting COVID-19!) and effective, but safety monitoring continues and remains a priority.

Several existing and some new strategies were put in place to monitor the safety of COVID-19 vaccines. Below, get ready to wade through some acronyms and we’ll outline a few of these strategies.

➡Vaccine Adverse Events Reporting System (VAERS): This is a biggie. Co-managed by the US Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA), VAERS has been around since 1990. Anyone can report possible side effects from a vaccine through VAERS and healthcare workers are required to report certain side effects. The CDC and FDA use this data to monitor safety. Reports of serious concerns (like hospitalization, life threatening illness, death, or serious harm that could cause disability) are investigated by VAERS staff. It’s really important to remember that just because something was reported to VAERS, it does not necessarily mean that a vaccine caused that problem. VAERS is not designed to determine if a vaccine causes specific adverse effects (it can’t distinguish between correlation and causation). It is meant to be an “early warning tool” and to help identify possible trends that need more study. If a concern for a trend is found, other vaccine safety monitoring programs conduct studies.

➡V-Safe: This is the new kid on the block and was developed for the COVID-19 vaccines. V-Safe is a new smartphone-based tool. Once you get vaccinated, you are offered the opportunity to sign up for V-Safe. It will serve as your vaccination record card and help you report to the CDC if you develop any side effects from the vaccine. V-Safe also has a COVID-19 Vaccine Pregnancy registry to collect safety monitoring information from people who receive the vaccine just before or during pregnancy.

➡Vaccine Safety Datalink (VSD): This is a longstanding collaboration between the CDC and 9 healthcare organizations from across the country (it’s been around since 1990). The VSD uses electronic health record data to answer questions about safety. When they are evaluating a possible side effect of a vaccine, the VSD looks at information on the vaccine (like which vaccine was given and when) and patient characteristics (like other health problems and ER or hospital visits) to pick out patterns. The VSD also will conduct studies based on potential concerns raised from reports made to VAERS.

➡Vaccine manufacturers: The vaccine developers are still conducting their clinical trials and safety monitoring.

COVID-19 vaccine safety is the most intensely and systematically monitored in vaccine history. Serious side effects (like anaphylaxis, thrombosis with thrombocytopenia syndrome, and myocarditis) have been reported, are incredibly rare, and were identified using this really strong vaccine safety monitoring system, proving the system works as designed. After over 390 million doses administered in the US alone, all signs are showing that these vaccines are incredibly safe and effective.

In the US, the COVID-19 vaccine is recommended for everyone 12 years old and up. If you have questions about COVID-19 vaccines, please ask your primary care clinician. They can work with you to make sure that you have your questions and concerns addressed.

Stay Safe Out There!

Those Nerdy Girls


CDC Ensuring the Safety of Covid19 Vaccine in the US

Vaccine Adverse Events Reporting System If you want instructions on how to review VAERS data yourself, check out this past DP post that will walk you through it.

Vaccine Safety Datalink


CDC Selected Adverse Events Reported after COVID-19 vaccination

Link to Original FB Post